ratio of word probabilities predicted from brain for cat and ant

cat	ant
top 10 words in brain distribution (in article): animal wear light century species design head time type breed	top 10 words in brain distribution (in article): animal species breed male hunt human female size head common
top 10 words in brain distribution (not in article): horse iron blade drink lamp steel wolf handle wine metal	top 10 words in brain distribution (not in article): cat wolf dog wild iron blade steel lion elephant handle
times more probable under cat 30 20 10 6 4 2.5 1.25 1 1.25 2.5 4 6 10 20 30 times more probable under ant (words not in the model)
The cat'" ("Felis catus"), also known as the domestic cat'" or "'house cat'" to distinguish it from other felines and felids, is a small predatory carnivorous species of crepuscular mammal that is valued by humans for its companionship and its ability to hunt vermin, snakes, scorpions, and other unwanted household pests. It has been associated with humans for at least 9,500 years. A skilled predator, the cat is known to hunt over 1,000 species for food. It can be trained to obey simple commands. Individual cats have also been known to learn on their own to manipulate simple mechanisms, such as doorknobs. Cats use a variety of vocalizations and types of body language for communication, including meowing, purring, hissing, growling, squeaking, chirping, clicking, and grunting. Cats may be the most popular pet in the world, with over 600 million in homes all over the world. They are also bred and shown as registered pedigree pets. This hobby is known as the "cat fancy." Until recently the cat was commonly believed to have been domesticated in ancient Egypt, where it was a cult animal. However a 2007 study found that the lines of descent of all house cats probably run through as few as five self-domesticating African Wildcats "(Felis silvestris lybica)" circa 8000 BC, in the Near East. Size. Cats typically weigh between 2.5 and 7 kg (5.5–16 pounds); however, some, such as the Maine Coon, can exceed. Some have been known to reach up to due to overfeeding. Conversely, very small cats (less than) have been reported. The largest cat ever was officially reported to have weighed in at about (46 lb 15.25 oz). The smallest cat ever officially recorded weighed around 3 lbs (1.36 kg). Cats average about in height and in head body length (males being larger than females), with tails averaging in length. Skeleton. Cats have 7 cervical vertebrae like almost all mammals, 13 thoracic vertebrae (humans have 12), 7 lumbar vertebrae (humans have 5), 3 sacral vertebrae like most mammals (humans have 5 because of their bipedal posture), and, except for Manx cats, 22 or 23 caudal vertebrae (humans have 3 to 5, fused into an internal coccyx). The extra lumbar and thoracic vertebrae account for the cat's enhanced spinal mobility and flexibility, compared with humans. The caudal vertebrae form the tail, used by the cat as a counterbalance to the body during quick movements. Cats also have free-floating clavicle bones, which allows them to pass their body through any space into which they can fit their heads. Mouth. Cats have highly specialized teeth for the killing of prey and the tearing of meat. The premolar and first molar together compose the carnassial pair on each side of the mouth, which efficiently functions to shear meat like a pair of scissors. While this is present in canids, it is highly developed in felines. The cat's tongue has sharp spines, or papillae, useful for retaining and ripping flesh from a carcass. These papillae are small backward-facing hooks that contain keratin which also assist in their grooming. As facilitated by their oral structure, cats use a variety of vocalizations and types of body language for communication, including meowing, purring, hissing, growling, squeaking, chirping, clicking, and grunting. Ears. Thirty-two individual muscles in each ear allow for a manner of directional hearing: a cat can move each ear independently of the other. Because of this mobility, a cat can move its body in one direction and point its ears in another direction. Most cats have straight ears pointing upward. Unlike dogs, flap-eared breeds are extremely rare (Scottish Folds are one such exceptional mutation.) When angry or frightened, a cat will lay back its ears, to accompany the growling or hissing sounds it makes. Cats also turn their ears back when they are playing, or to listen to a sound coming from behind them. The angle of cats' ears is an important clue to their mood. Legs. Cats, like dogs, are digitigrades. They walk directly on their toes, with the bones of their feet making up the lower part of the visible leg. Cats are capable of walking very precisely, because like all felines they directly register; that is, they place each hind paw (almost) directly in the print of the corresponding forepaw, minimizing noise and visible tracks. This also provides sure footing for their hind paws when they navigate rough terrain. Claws. Like nearly all members of family Felidae, cats have protractable claws. In their normal, relaxed position the claws are sheathed with the skin and fur around the toe pads. This keeps the claws sharp by preventing wear from contact with the ground and allows the silent stalking of prey. The claws on the forefeet are typically sharper than those on the hind feet. Cats can voluntarily extend their claws on one or more paws. They may extend their claws in hunting or self-defense, climbing, "kneading", or for extra traction on soft surfaces (bedspreads, thick rugs, etc.). It is also possible to make a cooperative cat extend its claws by carefully pressing both the top and bottom of the paw. The curved claws may become entangled in carpet or thick fabric, which may cause injury if the cat is unable to free itself. Most cats have five claws on their front paws, and four or five on their rear paws. Because of an ancient mutation, however, domestic and feral cats are prone to polydactylyism, (particularly in the east coast of Canada and north east coast of the United States) and may have six or seven toes. The fifth front claw (the dewclaw) is proximal to the other claws. More proximally, there is a protrusion which appears to be a sixth "finger". This special feature of the front paws, on the inside of the wrists, is the carpal pad, also found on the paws of big cats and dogs. It has no function in normal walking, but is thought to be an anti-skidding device used while jumping. Skin. Cats possess rather loose skin; this allows them to turn and confront a predator or another cat in a fight, even when it has a grip on them. This is also an advantage for veterinary purposes, as it simplifies injections. In fact, the lives of cats with kidney failure can sometimes be extended for years by the regular injection of large volumes of fluid subcutaneously, which serves as an alternative to dialysis. The particularly loose skin at the back of the neck is known as the "scruff", and is the area by which a mother cat grips her kittens to carry them. As a result, cats tend to become quiet and passive when gripped there. This behavior also extends into adulthood, when a male will grab the female by the scruff to immobilize her while he mounts, and to prevent her from running away as the mating process takes place. This technique can be useful when attempting to treat or move an uncooperative cat. However, since an adult cat is heavier than a kitten, a pet cat should never be carried by the scruff, but should instead have its weight supported at the rump and hind legs, and at the chest and front paws. Often (much like a small child) a cat will lie with its head and front paws over a person's shoulder, and its back legs and rump supported under the person's arm. Senses. Cat senses are attuned for hunting. Cats have highly advanced hearing, eyesight, taste, and touch receptors, making the cat extremely sensitive among mammals. Cats' night vision is superior to humans although their vision in daylight is inferior. Cat eyes have a tapetum lucidum and cat eyes that are blue typically lack melanin and hence can show the red-eye effect (see odd-eyed cat). Humans and cats have a similar range of hearing on the low end of the scale, but cats can hear much higher-pitched sounds, up to 64 kHz, which is 1.6 octaves above the range of a human, and even one octave above the range of a dog. A domestic cat's sense of smell is about fourteen times as strong as a human's. Due to a mutation in an early cat ancestor, one of two genes necessary to taste sweetness may have been lost by the cat family. To aid with navigation and sensation, cats have dozens of movable vibrissae (whiskers) over their body, especially their face. Metabolism. Cats conserve energy by sleeping more than most animals, especially as they grow older. The daily duration of sleep varies, usually 12–16 hours, with 13–14 being the average. Some cats can sleep as much as 20 hours in a 24-hour period. The term "cat nap" refers to the cat's ability to fall asleep (lightly) for a brief period and has entered the English lexicon – someone who nods off for a few minutes is said to be "taking a cat nap". Due to their crepuscular nature, cats are often known to enter a period of increased activity and playfulness during the evening and early morning, dubbed the "evening crazies", "night crazies", "elevenses", or "mad half-hour" by some. The temperament of a cat can vary depending on the breed and socialization. Cats with oriental body types tend to be thinner and more active, while cats that have a cobby body type tend to be heavier and less active. The normal body temperature of a cat is between 38 and 39 °C (101 and 102.2 °F). A cat is considered febrile (hyperthermic) if it has a temperature of 39.5 °C (103 °F) or greater, or hypothermic if less than 37.5 °C (100 °F). For comparison, humans have a normal temperature of approximately 36.8 °C (98.6 °F). A domestic cat's normal heart rate ranges from 140 to 220 beats per minute, and is largely dependent on how excited the cat is. For a cat at rest, the average heart rate usually is between 150 and 180 bpm, about twice that of a human (average 80 bpm). Genetics. A 2007 study published in the journal "Science" asserts that all house cats are descended from a group of self-domesticating desert wildcats "Felis silvestris lybica" circa 10,000 years ago, in the Near East. The domesticated cat and its closest wild ancestor are both diploid organisms that possess 38 chromosomes, in which over 200 heritable genetic defects have been identified, many homologous to human inborn errors. Specific metabolic defects have been identified underlying many of these feline diseases. There are several genes responsible for the hair color identified. The combination of them gives different phenotypes. Features like hair length, lack of tail, or presence of a very short tail (bobtail cat) are also determined by single alleles and modified by polygenes. The Cat Genome Project, sponsored by the Laboratory of Genomic Diversity at the U.S. National Cancer Institute Frederick Cancer Research and Development Center in Frederick, Maryland, focuses on the development of the cat as an animal model for human hereditary disease, infectious disease, genome evolution, comparative research initiatives within the family Felidae, and forensic potential. All felines, including the big cats, have a genetic anomaly that may prevent them from tasting sweetness, which is a likely factor for their indifference to or avoidance of fruits, berries, and other sugary foods. Feeding and diet. Cats feed on small prey such as insects, birds, and rodents. Feral cats, or house cats who are free-fed, consume about 8 to 16 small meals in a single day. Despite this, adult cats can adapt to being fed once a day. Cats are classified as obligate carnivores, because their physiology is geared toward efficient processing of meat, and lacks efficient processes for digesting plant matter. The cat cannot produce its own taurine (an essential organic acid), and, as it is contained in flesh, the cat must eat flesh to survive (see Taurine and cats). Similarly as with its teeth, a cat's digestive tract has become specialized over time to suit meat eating, having shortened in length only to those segments of intestine best able to break down proteins and fats from animal flesh. This trait severely limits the cat's ability to properly digest, metabolize, and absorb plant-derived nutrients, as well as certain fatty acids. For example, taurine is scarce in plants but abundant in meats. It is a key amino sulfonic acid for eye health in cats. Taurine deficiency can cause a condition called macular degeneration wherein the cat's retina slowly degenerates, eventually causing irreversible blindness. Despite the cat's meat-oriented physiology, it is still quite common for a cat to supplement its carnivorous diet with small amounts of grass, leaves, shrubs, houseplants, or other plant matter. One theory suggests this behavior helps cats regurgitate if their digestion is upset; another is that it introduces fiber or trace minerals into the diet. In this context, caution is recommended for cat owners because some houseplants are harmful to cats. For example, the leaves of the Easter Lily can cause permanent and life-threatening kidney damage to cats, and Philodendron are also poisonous to cats. The Cat Fanciers' Association has a full list of plants harmful to cats. There are several vegetarian or vegan commercially available cat foods supplemented with chemically synthesized taurine and other added nutrients that attempt to address nutritional shortfalls. Cats can be selective eaters (which may be due in some way to the aforementioned mutation which caused their species to lose sugar-tasting ability). However, cats generally cannot tolerate lack of food for more than 36 hours without risking liver damage. Cats have a fondness for catnip, which is sensed by their olfactory systems. Many enjoy consuming catnip, and most will often roll in it, paw at it, and occasionally chew on it. Cats also can also develop odd eating habits. Some cats like to eat or chew on other things like plastic, paper, string, wool, or even coal. This condition is called pica and can threaten the cat's health depending on the amount and toxicity of the non-food items eaten. The condition's name comes from the Latin word for magpie, a bird which is reputed to eat almost anything. Toxic sensitivity. The liver of a cat is less effective at detoxification than those of other animals, including humans and dogs; therefore exposure to many common substances considered safe for households may be dangerous to them. In general, the cat's environment should be examined for the presence of such toxins and the problem corrected or alleviated as much as possible; in addition, where sudden or prolonged serious illness without obvious cause is observed, the possibility of toxicity must be considered, and the veterinarian informed of any such substances to which the cat may have had access. For instance, the common painkiller paracetamol or acetaminophen, sold under brand names such as Tylenol and Panadol, is extremely toxic to cats; because they naturally lack enzymes needed to digest it, even minute portions of doses safe for humans can be fatal and any suspected ingestion warrants immediate veterinary attention. Even aspirin, which is sometimes used to treat arthritis in cats, is much more toxic to them than to humans and must be administered cautiously. Similarly, application of minoxidil (Rogaine) to the skin of cats, either accidental or by well-meaning owners attempting to counter loss of fur, has sometimes proved fatal. In addition to such obvious dangers as insecticides and weed killers, other common household substances that should be used with caution in areas where cats may be exposed to them include mothballs and other naphthalene products, as well as phenol based products often used for cleaning and disinfecting near cats' feeding areas or litter boxes, such as Pine-Sol, Dettol (Lysol), hexachlorophene, "etc." which, although they are widely used without problem, have been sometimes seen to be fatal. Ethylene glycol, often used as an automotive antifreeze, is particularly appealing to cats, and as little as a teaspoonful can be fatal. Essential oils are toxic to cats and there have been reported cases of serious illnesses caused by tea tree oil, and tea tree oil-based flea treatments and shampoos. Many human foods are somewhat toxic to cats; theobromine in chocolate can cause theobromine poisoning, for instance, although few cats will eat chocolate. Toxicity in cats ingesting relatively large amounts of onions or garlic has also been reported. Even such seemingly safe items as cat food packaged in pull tab tin cans have been statistically linked to hyperthyroidism; although the connection is far from proven, suspicion has fallen on the use of bisphenol A-based plastics, another phenol based product as discussed above, to seal such cans. Many houseplants are at least somewhat toxic to many species, cats included and the consumption of such plants by cats is to be avoided. Sociability. For cats, life in close proximity with humans (and other animals kept by humans) amounts to a "symbiotic social adaptation" which has developed over thousands of years. It has been suggested that, ethologically, the human keeper of a cat functions as a sort of surrogate for the cat's mother, and that adult domestic cats live their lives in a kind of extended kittenhood, a form of behavioral neoteny. Cats may express affection towards their human companions, especially if they imprint on them at a very young age and are treated with consistent affection. Regardless of the average sociability of any given cat or of cats in general, there are still any number of cats who meet or exceed the negative feline stereotype insofar as being poorly socialized. Older cats have also been reported to sometimes develop aggressiveness towards kittens, which may include biting and scratching; this type of behavior is known as Feline Asocial Aggression. Cohabitation. One may see natural house cat behavior by observing feral domestic cats, which are social enough to form colonies. Each cat in a colony holds a distinct territory, with sexually active males having the largest territories, and neutered cats having the smallest. Between these territories are neutral areas where cats watch and greet one another without territorial conflicts. Outside these neutral areas, territory holders usually aggressively chase away stranger cats, at first by staring, hissing, and growling, and if that does not work, by short but noisy and violent attacks. Despite cohabitation in colonies, cats do not have a social survival strategy, or a pack mentality. This mainly means that an individual cat takes care of all basic needs on its own (e.g., finding food, and defending itself), and thus cats are always lone hunters; they do not hunt in groups as dogs or lions do. Cats frequently tonguebathe themselves (see hygiene). The chemistry of their saliva, expended during their frequent grooming, appears to be a natural deodorant. Thus, a cat's cleanliness would aid in decreasing the chance a prey animal could notice the cat's presence. By contrast, dog odor is an advantage in hunting, for a dog is a pack hunter; part of the pack stations itself upwind, and its odor drives prey towards the rest of the pack stationed downwind. This requires a cooperative effort, which in turn requires communication skills. No such communication skills are required of a lone hunter. Fighting. When engaged in feline-to-feline combat for self-defense, territory, reproduction, or dominance, fighting cats make themselves appear more impressive and threatening by raising their fur and arching their backs, thus increasing their apparent size. Cats also behave this way while playing. Attacks usually comprise powerful slaps to the face and body with the forepaws as well as bites, but serious damage is rare; usually the loser runs away with little more than a few scratches to the face, and perhaps the ears. Cats will also throw themselves to the ground in a defensive posture to rake with their powerful hind legs. Normally, serious negative effects will be limited to possible infections of the scratches and bites, though these have been known to sometimes kill cats if untreated. In addition, such fighting is believed to be the primary route of transmission of feline immunodeficiency virus (FIV). Sexually active males will usually be in many fights during their lives, and often have decidedly battered faces with obvious scars and cuts to the ears and nose. Not only males will fight; females will also fight over territory or to defend their kittens. Play. Domestic cats, especially young kittens, are known for their love of play. This behavior mimics hunting and is important in helping kittens learn to stalk, capture, and kill prey. Many cats cannot resist a dangling piece of string, or a piece of rope drawn randomly and enticingly across the floor. This well known love of string is often depicted in cartoons and photographs, which show kittens or cats playing with balls of yarn. It is probably related to hunting instincts, including the common practice of kittens hunting their mother's and each other's tails. If string is ingested, however, it can become caught in the cat’s stomach or intestines, causing illness, or in extreme cases, death. Due to possible complications caused by ingesting a string, string play is sometimes replaced with a laser pointer's dot, which some cats will chase. While caution is called for, there are no documented cases of feline eye damage from a laser pointer, and the combination of precision needed and low energy involved make it a remote risk. A common compromise is to use the laser pointer to draw the cat to a prepositioned toy so the cat gets a reward at the end of the chase. A regular flashlight with a well-focused light spot has been commonly used in such play for decades, preceding the availability of consumer laser pointers. Cats will also engage in play fighting, with each other and with human partners. Humans "wrestling" with a supine cat, however, should be wary: if the cat is overstimulated or startled it may decide that the play has turned serious and cease to pull its punches; this can lead to serious scratches and occasionally even bites. Hunting. Much like their big cat relatives, domestic and feral cats are very effective predators. Domestic felines ambush or pounce upon and immobilize vertebrate prey using tactics similar to those of leopards and tigers. Having overpowered such prey, a cat delivers a lethal neck bite with its long canine teeth that either severs the prey's spinal cord with irreversible paralysis to prey, causes fatal bleeding by puncturing the carotid artery or the jugular vein, or asphyxiates the prey by crushing its trachea. One poorly understood element of cat hunting behavior is the presentation of prey to human owners. Ethologist Paul Leyhausen proposed that cats adopt humans into their social group, and share excess kill with others in the group according to the local pecking order, in which humans are placed at or near the top. However, anthropologist and animal scientist Desmond Morris in his 1986 book "Catwatching" suggests that when cats bring home mice or birds they have caught, they are teaching their human to hunt, or helping their human as if feeding (his words) "an elderly, inept kitten". Another possibility is that presenting the kill might be a relic of a kitten's behavior of demonstrating for its mother's approval that it has developed the necessary skill for hunting. Indoor cats will often retain their hunting instinct and deliver small household items to their owners, such as watches, pens, pencils, and other objects they can carry in their mouths. Reproduction. Cats are seasonally polyestrous, which means they may have many periods of heat over the course of a year. A heat period lasts about 4 to 7 days if the female is bred; if she is not, the heat period lasts longer. Multiple males will be attracted to a female in heat. The males will fight over her, and the victor wins the right to mate. At first, the female will reject the male, but eventually the female will allow the male to mate. The female will give a loud yowl as the male pulls out of her. After mating, the female will give herself a thorough wash. If a male attempts to breed with her at this point, the female will attack him. Once the female is done grooming, the cycle will repeat. The male cat's penis has spines which point backwards. Upon withdrawal of the penis, the spines rake the walls of the female's vagina, which may cause ovulation. Because this does not always occur, females are rarely impregnated by the first male with which they mate. Furthermore, cats are superfecund; that is, a female may mate with more than one male when she is in heat, meaning different kittens in a litter may have different fathers. The gestation period for cats is approximately 63–65 days. The size of a litter averages three to five kittens, with the first litter usually smaller than subsequent litters. Kittens are weaned at between six and seven weeks, and cats normally reach sexual maturity at 5–10 months (females) and to 5–7 months (males). Cats are ready to go to new homes at about 12 weeks old (the recommended minimum age by Fédération Internationale Féline), or when they are ready to leave their mother. Cats can be surgically sterilized (spayed or castrated) as early as 6–8 weeks to limit unwanted reproduction. This surgery also prevents undesirable sex-related behavior, such as territory marking (spraying urine) in males and yowling (calling) in females. If a cat is neutered after such behavior has been learned, however, then the behavior may persist. Hygiene. Cats are known for their fastidious cleanliness. They groom themselves by licking their fur, employing their hooked papillae and saliva. As mentioned, their saliva is a powerful cleaning agent and deodorant. Many cats also enjoy grooming humans or other cats. Sometimes the act of grooming another cat is initiated as an assertion of superior position in the pecking order of a group (dominance grooming). Some cats occasionally regurgitate hairballs of fur that have collected in their stomachs as a result of their grooming. Longhaired cats are more prone to this than shorthaired cats. Hairballs can be prevented with certain cat foods and remedies that ease elimination of the hair and regular grooming of the coat with a comb or stiff brush. Scratching. Cats are naturally driven to periodically hook their front claws into suitable surfaces and pull backwards, in order to clean the claws and remove the worn outer sheath, as well as exercise and stretch their muscles. This scratching behavior seems enjoyable to the cat, and even declawed cats will go through elaborate scratching routines with every evidence of great satisfaction, despite the total lack of results. Some researchers believe this is due to scent glands located in their pads, and that scratching is effectively a part of marking territory. Fondness for heights. Most breeds of cat have a noted fondness for settling in high places, or perching. Animal behaviorists have posited a number of explanations, the most common being that height gives the cat a better observation point, allowing it to survey its territory and become aware of activities of people and other pets in the area. In the wild, a higher place may serve as a concealed site from which to hunt; domestic cats are known to strike prey by pouncing from such a perch as a tree branch, as does a leopard. Height, therefore, can also give cats a sense of security. During a fall from a high place, a cat can reflexively twist its body and right itself using its acute sense of balance and flexibility. This is known as the cat's "righting reflex". It always rights itself in the same way, provided it has the time to do so, during a fall. The height required for this to occur in most cats (safely) is around 90 cm (3 feet). Cats without a tail also have this ability, since a cat mostly moves its hind legs and relies on conservation of angular momentum to set up for landing, and the tail is in fact little used for this feat. However, cats' fondness for high spaces can dangerously test the righting reflex. The American Society for the Prevention of Cruelty to Animals warns owners to safeguard the more dangerous perches in their homes, to avoid "high-rise syndrome", where an overconfident cat falls from an extreme height. Habitat. The African Wildcat ("Felis silvestris lybica"), ancestor of the domestic cat, is believed to have evolved in a desert climate, as evident in the behavior common to both the domestic and wild forms. Wildcats ("Felis sylvestris") are native to all continents other than Australia and Antarctica, although feral cats have become apex predators in the Australian Outback where they are menaces to wildlife. Their feces are usually dry, and cats prefer to bury them in sandy places. Urine is highly concentrated, which allows the cat to retain as much fluid as possible. They are able to remain motionless for long periods, especially when observing prey and preparing to pounce. In North Africa there are still small wildcats that are probably related closely to the ancestors of today's domesticated cat breeds. Being closely related to desert animals, cats enjoy heat and solar exposure, often sleeping in a sunny area during the heat of the day, as part of a general preference for warm temperatures. Where humans typically start to feel uncomfortable when their skin temperature gets higher than about 44.5 °C (112 °F), by contrast cats do not start to show signs of discomfort until their skin reaches about 52 °C (126 °F). Overall, cats can easily withstand the heat and cold of a temperate climate, so long as the cold is not for extended periods. Although certain breeds such as the Norwegian Forest Cat and Maine Coon have developed heavier coats of fur than other cats, they have little resistance against moist cold (e.g., fog, rain, and snow) and struggle to maintain their 39 °C (102 °F) body temperature when wet. In direct relation to that fact, most cats dislike immersion in water. One major exception is the Turkish Van breed which has an unusual fondness for water. Abyssinians and Bengals are also reported to be more tolerant of water than most cats. Impact of hunting. The domestic cat hunts and eats over a thousand species, many of them invertebrates, especially insects — many big cats will eat fewer than a hundred different species. Although theoretically big cats can kill most of these species as well, they often do not due to the relatively low nutritional content that smaller animals provide for the effort. An exception is the leopard, which commonly hunts rabbits and many other smaller animals. Even well-fed domestic cats may hunt and kill birds, mice, rats, scorpions, cockroaches, grasshoppers, and other small animals in their environment. As a consequence of their exceptional hunting ability, cats can be quite destructive to ecosystems in which they are not native, where local species have not had time to adapt to feline introduction. In some cases, cats have contributed to or caused extinctions — for example, see the case of the Stephens Island Wren. Due to their hunting behavior, in many countries feral cats are considered pests. Domestic cats are occasionally also required to have contained cat runs or to be kept inside entirely, as they can be hazardous to locally endangered bird species. For instance, various municipalities in Australia have enacted such legislation. In some localities, owners fit their cat with a bell in order to warn prey of its approach (although some cats may figure out how and when the bell works, thereby learning more careful movements to avoid the ringing). Domestication. In 2004, a grave was excavated in Cyprus that contained the skeletons, laid close to one another, of both a human and a cat. The grave is estimated to be 9,500 years old, pushing back the earliest known feline-human association significantly. Like some other domesticated animals, cats live in a mutualistic arrangement with humans. It is believed that the benefit of removing rats and mice from humans' food stores outweighed the trouble of extending the protection of a human settlement to a formerly wild animal, almost certainly for humans who had adopted a farming economy. Unlike the dog, which also hunts and kills rodents, the cat does not eat grains, fruits, or vegetables. In modern rural areas, farms often have dozens of semi-feral cats. Hunting in the barns and the fields, they kill and eat rodents that would otherwise spoil large parts of the grain crop. Many pet cats successfully hunt and kill rabbits, rodents, birds, lizards, frogs, fish, and large insects by instinct, but might not eat their prey. In modern urban areas, some people find feral and free-roaming pet cats annoying and intrusive. Unaltered cats can engage in persistent nighttime calling (termed caterwauling) and defecation or "marking" of private property. Indoor confinement of pets and TNR programs for feral cats can help; some people also use cat deterrents to discourage cats from entering their property. In captivity, indoor cats typically live 14 to 20 years, though the oldest known cat lived to age 36. Domesticated cats tend to live longer if they are not permitted to go outdoors (reducing the risk of injury from fights or accidents and exposure to diseases) and if they are neutered. Some such benefits are: castrated male cats cannot develop testicular cancer, spayed female cats cannot develop ovarian cancer, and both have a reduced risk of mammary cancer. Interaction with humans. Human attitudes toward cats vary widely. Some people keep cats for casual companionship as pets. Cats are also bred and shown as registered pedigree pets, in a hobby known as the cat fancy. Because of their small size, domesticated house cats pose almost no major danger to adult humans — the main hazard is the possibility of infection (e.g., cat scratch disease, or, rarely, rabies) from a cat bite or scratch. Cats can also potentially inflict severe scratches or puncture an eye, though this is quite rare (although dogs have been known to be blinded by cats in fights, where the cat specifically and accurately targeted the eyes of the larger animal). Allergens. Allergic reactions to cat dander and or cat saliva inspire one of the most common reasons people cite for disliking cats. Some humans who are allergic to cats—typically manifested by hay fever, asthma, or a skin rash—quickly acclimate themselves to a particular animal and live comfortably in the same house with it, while retaining an allergy to cats in general. However, this should not be depended upon. Many humans find the rewards of cat companionship outweigh the discomfort and problems associated with these allergens. Some cope with the problem by taking prescription allergy medicine, along with bathing their cats frequently (weekly bathing will eliminate about 90% of the cat dander present in the environment). There are also attempts to breed cats that are less likely to provoke an allergic reaction. Trainability. Some owners seek to train their cat in performing tricks commonly exhibited by dogs, such as jumping, though this is rare. Individual cats have been known to learn to manipulate simple mechanisms, like sink faucets, by themselves or after prompting encouraging. With effort and patience on the part of an owner, the average cat can usually be trained to at least obey simple commands such as "get off the furniture" or "come to dinner". In general though, the seeming intractability of the ordinary house cat to training has long inspired the simile 'like herding cats', as a general expression to describe any situation with a stubborn or uncooperative learner. Indoor scratching. Cats are naturally driven to periodically hook their front claws into suitable surfaces and pull backwards, in order to clean the claws. Indoor cats benefit from being provided with a scratching post so that they are less likely to use carpet or furniture which they can easily ruin. Commercial scratching posts typically are covered in carpeting or upholstery, but some authorities advise against this practice, as not making it clear to the cat which surfaces are permissible and which are not; they suggest using a plain wooden surface, or reversing the carpeting on the posts so that the rougher texture of the carpet backing is a more attractive alternative to the cat than the floor covering. Scratching posts made of sisal rope or corrugated cardboard are also commonly found. Some indoor cats, however, especially those that were taken as kittens from feral colonies, may not understand the concept of a scratching post, and as a result will ignore it. Although scratching can serve cats to keep their claws from growing excessively long, their nails can be trimmed if necessary with a small nail trimmer designed for humans, or a small pair of electrician's diagonal cutting pliers, or a guillotine type cutter specifically designed for animal nail trimming. Care must always be taken to avoid cutting the quick of the claw, analogous to cutting into the tip of a finger and equally painful and bloody. The position of the quick can be easily seen through the translucent nail of a cat with light colored claws but not in cats with dark colored nails, who therefore require carefully trimming of only small amounts from the nails. Scratching can be reduced and even eliminated by disciplining the cat with a quick spritz from a water bottle when the cat is scratching or by applying a product called Sticky Paws (similar to double-sided tape) to the surface the cat is prone to scratch. Cats are also repelled by citrus scents, and a citrus-scented product may also help stop unwanted furniture destruction. Pet supply stores also sell bitter apple spray, which cats do not like and will generally avoid. Declawing. Declawing is a surgical procedure, known as "onychectomy", to remove the claw and first bone of each digit of a cat's paws. Declawing is most commonly only performed on front feet. Declawing may be performed to prevent the cat from damaging furniture. Additionally, declawing may be performed on vicious cats, cats that frequently fight with other pets, or cats that are too efficient at predation of animals. In the United States, landlords sometimes require that tenants' cats be declawed. Declawing is controversial and is uncommon outside of North America. In many countries, it is prohibited by animal cruelty laws. In the US it is condemned by both the Humane Society of the United States and the American Society for the Prevention of Cruelty to Animals and many veterinarians refuse to perform the procedure. Waste. Indoor cats are usually provided with a litter box containing litter, typically bentonite, but sometimes other absorbent material such as shredded paper or wood chips, or sometimes sand or similar material. This arrangement serves the same purpose as a toilet for humans. It should be cleaned daily and changed often, depending on the number of cats in a household and the type of litter; if it is not kept clean, a cat may be fastidious enough to find other locations in the house for urination or defecation. This may also happen for other reasons; for instance, if a cat becomes constipated and defecation is uncomfortable, it may associate the discomfort with the litter box and avoid it in favor of another location. A litterbox is recommended for indoor-outdoor cats as well. Daily attention to the litter box also serves as a monitor of the cat's health. Numerous variations on litter and litter box design exist, including some which automatically sift the litter after each use. Bentonite or clumping litter is a variation which absorbs urine into clumps which can be sifted out along with feces, and thus stays cleaner	A phylogeny of the extant ant subfamilies. "'Ants'" are social insects of the family "'Formicidae'", and along with the related wasps and bees, they belong to the order Hymenoptera. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants. Today, more than 12,000 species are classified with upper estimates of about 14,000 species. They are easily identified by their elbowed antennae and a distinctive node-like structure that forms a slender waist. Ants form colonies that range in size from a few dozen predatory individuals living in small natural cavities to highly organised colonies which may occupy large territories and consist of millions of individuals. These larger colonies consist mostly of sterile wingless females forming castes of "workers", "soldiers", or other specialised groups. Ant colonies also have some fertile males called "drones" and one or more fertile females called "queens". The colonies are sometimes described as superorganisms because ants appear to operate as a unified entity, collectively working together to support the colony. Ants have colonised almost every landmass on Earth. The only places lacking indigenous ants are Antarctica and certain remote or inhospitable islands. Ants thrive in most ecosystems, and may form 15–25% of the terrestrial animal biomass. Their success has been attributed to their social organisation and their ability to modify habitats, tap resources, and defend themselves. Their long co-evolution with other species has led to mimetic, commensal, parasitic, and mutualistic relationships. Ant societies have division of labour, communication between individuals, and an ability to solve complex problems. These parallels with human societies have long been an inspiration and subject of study. Many human cultures make use of ants in cuisine, medication and rituals. Some species are valued in their role as biological pest control agents. However, their ability to exploit resources brings ants into conflict with humans, as they can damage crops and invade buildings. Some species, such as the red imported fire ant, are regarded as invasive species, since they have establish themselves in new areas where they may be accidentally introduced. Taxonomy and evolution. The family Formicidae belongs to the order Hymenoptera, which also includes sawflies, bees and wasps. Ants evolved from a lineage within the vespoid wasps. Phylogenetic analysis suggests that ants arose in the mid-Cretaceous period about 110 to 130 million years ago. After the rise of flowering plants about 100 million years ago they diversified and assumed ecological dominance around 60 million years ago. In 1966, E. O. Wilson and his colleagues identified the fossil remains of an ant ("Sphecomyrma freyi") that lived in the Cretaceous period. The specimen, trapped in amber dating back to more than 80 million years ago, has features of both ants and wasps. "Sphecomyrma" was probably a ground forager but some suggest on the basis of groups such as the Leptanillinae and Martialinae that primitive ants were likely to have been predators under the soil surface. During the Cretaceous period, only a few species of primitive ants ranged widely on the Laurasian super-continent (the northern hemisphere). They were scarce in comparison to other insects, representing about 1% of the insect population. Ants became dominant after adaptive radiation at the beginning of the Tertiary period. By the Oligocene and Miocene ants had come to represent 20–40% of all insects found in major fossil deposits. Of the species that lived in the Eocene epoch, approximately one in ten genera survive to the present. Genera surviving today comprise 56% of the genera in Baltic amber fossils (early Oligocene), and 92% of the genera in Dominican amber fossils (apparently early Miocene). Termites, though sometimes called "white ants", are not ants and belong to the order Isoptera. The termites are actually more closely related to cockroaches and mantids. The fact that ants and termites are both eusocial came about by Convergent evolution. Velvet ants look like large ants, but are wingless female wasps. Etymology. The word "ant" is derived from "ante" of Middle English which is derived from "æmette" and "emmett" of Old English and is related to the Old High German "āmeiza" from which comes "Ameise", the German word for ant. The family name "Formicidae" is derived from the Latin "formīca" ("ant") from which derived Portuguese "formiga", Spanish "hormiga", Romanian "furnică", French "fourmi", etc. Distribution and diversity. Ants are found on all continents except Antarctica and only a few large islands such as Greenland, Iceland, parts of Polynesia and the Hawaiian Islands lack native ant species. Ants occupy a wide range of ecological niches, and are able to exploit a wide range of food resources either as direct or indirect herbivores, predators and scavengers. Most species are omnivorous generalists but a few are specialist feeders. Their ecological dominance may be measured by their biomass, and estimates in different environments suggest that they contribute 15–20% (on average and nearly 25% in the tropics) of the total terrestrial animal biomass, which exceeds that of the vertebrates. Ants range in size from. Their colours vary; most are red or black, green is less common, and some tropical species have a metallic lustre. More than 12,000 species are currently known (with upper estimates of about 14,000), with the greatest diversity in the tropics. Taxonomic studies continue to resolve the classification and systematics of ants. Online databases of ant species, including AntBase and the Hymenoptera Name Server, help to keep track of the known and newly described species. The relative ease with which ants can be sampled and studied in ecosystems has made them useful as indicator species in biodiversity studies. Morphology. Ants are distinct in their morphology from other insects in having elbowed antennae, metapleural glands, and a strong constriction of their second abdominal segment into a node-like petiole. The head, mesosoma and metasoma or gaster are the three distinct body segments. The petiole forms a narrow waist between their mesosoma (thorax plus the first abdominal segment, which is fused to it) and gaster (abdomen less the abdominal segments in the petiole). The petiole can be formed by one or two nodes (the second alone, or the second and third abdominal segments). Like other insects, ants have an exoskeleton, an external covering that provides a protective casing around the body and a point of attachment for muscles, in contrast to the internal skeletons of humans and other vertebrates. Insects do not have lungs; oxygen and other gases like carbon dioxide pass through their exoskeleton through tiny valves called spiracles. Insects also lack closed blood vessels; instead, they have a long, thin, perforated tube along the top of the body (called the "dorsal aorta") that functions like a heart, and pumps haemolymph towards the head, thus driving the circulation of the internal fluids. The nervous system consists of a ventral nerve cord that runs the length of the body, with several ganglia and branches along the way reaching into the extremities of the appendages. An ant's head contains many sensory organs. Like most insects, ants have compound eyes made from numerous tiny lenses attached together. Ants' eyes are good for acute movement detection but do not give a high resolution. They also have three small ocelli (simple eyes) on the top of the head that detect light levels and polarisation. Compared to vertebrates, most ants have poor-to-mediocre eyesight and a few subterranean species are completely blind. Some ants such as Australia's bulldog ant, however, have exceptional vision. Two antennae ("feelers") are attached to the head; these organs detect chemicals, air currents and vibrations; they are also used to transmit and receive signals through touch. The head has two strong jaws, the mandibles, used to carry food, manipulate objects, construct nests, and for defence. In some species a small pocket (infrabuccal chamber) inside the mouth stores food, so it can be passed to other ants or their larvae. All six legs are attached to the mesosoma ("thorax"). A hooked claw at the end of each leg helps ants to climb and hang onto surfaces. Most queens and male ants have wings; queens shed the wings after the nuptial flight, leaving visible stubs, a distinguishing feature of queens. However, wingless queens (ergatoids) and males occur in a few species. The metasoma (the "abdomen") of the ant houses important internal organs, including those of the reproductive, respiratory (tracheae) and excretory systems. Workers of many species have their egg-laying structures modified into stings that are used for subduing prey and defending their nests. Polymorphism. In the colonies of a few ant species, there are physical castes—workers in distinct size-classes, called minor, median, and major workers. Often the larger ants have disproportionately larger heads, and correspondingly stronger mandibles. Such individuals are sometimes called "soldier" ants because their stronger mandibles make them more effective in fighting, although they are still workers and their "duties" typically do not vary greatly from the minor or median workers. In a few species the median workers are absent, creating a sharp divide between the minors and majors. Weaver ants, for example, have a distinct bimodal size distribution. Some other species show continuous variation in the size of workers. The smallest and largest workers in "Pheidologeton diversus" show nearly a 500-fold difference in their dry-weights. Workers cannot mate; however, because of the haplodiploid sex-determination system in ants, workers of a number of species can lay unfertilised eggs that become fully fertile haploid males. The role of workers may change with their age and in some species, such as honeypot ants, young workers are fed until their gasters are distended, and act as living food storage vessels. These food storage workers are called "repletes". This polymorphism in morphology and behaviour of workers was initially thought to be determined by environmental factors such as nutrition and hormones which led to different developmental paths; however, genetic differences between worker castes have been noted in "Acromyrmex" sp. These polymorphisms are caused by relatively small genetic changes; differences in a single gene of "Solenopsis invicta" can decide whether the colony will have single or multiple queens. The Australian jack jumper ant ("Myrmecia pilosula"), has only a single pair of chromosomes (males have just one chromosome as they are haploid), the lowest number known for any animal, making it an interesting subject for studies in the genetics and developmental biology of social insects. Development and reproduction. The life of an ant starts from an egg. If the egg is fertilised, the progeny will be female (diploid); if not, it will be male (haploid). Ants develop by complete metamorphosis with the larval stages passing through a pupal stage before emerging as an adult. The larva is largely immobile and is fed and cared for by workers. Food is given to the larvae by trophallaxis, a process in which an ant regurgitates liquid food held in its crop. This is also how adults share food, stored in the "social stomach", among themselves. Larvae may also be provided with solid food such as trophic eggs, pieces of prey and seeds brought back by foraging workers and may even be transported directly to captured prey in some species. The larvae grow through a series of moults and enter the pupal stage. The pupa has the appendages free and not fused to the body as in a butterfly pupa. The differentiation into queens and workers (which are both female), and different castes of workers (when they exist), is determined by the nutrition the larvae obtain. Larvae and pupae need to be kept at fairly constant temperatures to ensure proper development, and so are often moved around the various brood chambers within the colony. A new worker spends the first few days of its adult life caring for the queen and young. It then graduates to digging and other nest work, and later to defending the nest and foraging. These changes are sometimes fairly sudden, and define what are called temporal castes. An explanation for the sequence is suggested by the high casualties involved in foraging, making it an acceptable risk only for ants that are older and are likely to die soon of natural causes. Most ant species have a system in which only the queen and breeding females have the ability to mate. Contrary to popular belief, some ant nests have multiple queens while others can exist without queens. Workers with the ability to reproduce are called "gamergates" and colonies that lack queens are then called gamergate colonies; colonies with queens are said to be queen-right. The winged male ants, called drones, emerge from pupae along with the breeding females (although some species, like army ants, have wingless queens), and do nothing in life except eat and mate. During the short breeding period, the reproductives, excluding the colony queen, are carried outside where other colonies of similar species are doing the same. Then, all the winged breeding ants take flight. Mating occurs in flight and the males die shortly afterwards. Females of some species mate with multiple males. Mated females then seek a suitable place to begin a colony. There, they break off their wings and begin to lay and care for eggs. The females store the sperm they obtain during their nuptial flight to selectively fertilise future eggs. The first workers to hatch are weak and smaller than later workers, but they begin to serve the colony immediately. They enlarge the nest, forage for food and care for the other eggs. This is how new colonies start in most species. Species that have multiple queens may have a queen leaving the nest along with some workers to found a colony at a new site, a process akin to swarming in honeybees. Ant colonies can be long-lived. The queens can live for up to 30 years, and workers live from 1 to 3 years. Males, however, are more transitory, and survive only a few weeks. Ant queens are estimated to live 100 times longer than solitary insects of a similar size. Ants are active all year long in the tropics but, in cooler regions, survive the winter in a state of dormancy or inactivity. The forms of inactivity are varied and some temperate species have larvae going into the inactive state (diapause), while in others, the adults alone pass the winter in a state of reduced activity. Communication. Ants communicate with each other using pheromones. These chemical signals are more developed in ants than in other hymenopteran groups. Like other insects, ants perceive smells with their long, thin and mobile antennae. The paired antennae provide information about the direction and intensity of scents. Since most ants live on the ground, they use the soil surface to leave pheromone trails that can be followed by other ants. In species that forage in groups, a forager that finds food marks a trail on the way back to the colony; this trail is followed by other ants, these ants then reinforce the trail when they head back with food to the colony. When the food source is exhausted, no new trails are marked by returning ants and the scent slowly dissipates. This behaviour helps ants deal with changes in their environment. For instance, when an established path to a food source is blocked by an obstacle, the foragers leave the path to explore new routes. If an ant is successful, it leaves a new trail marking the shortest route on its return. Successful trails are followed by more ants, reinforcing better routes and gradually finding the best path. Ants use pheromones for more than just making trails. A crushed ant emits an alarm pheromone that sends nearby ants into an attack frenzy and attracts more ants from further away. Several ant species even use "propaganda pheromones" to confuse enemy ants and make them fight among themselves. Pheromones are produced by a wide range of structures including Dufour's glands, poison glands and glands on the hindgut, pygidium, rectum, sternum and hind tibia. Pheromones are also exchanged mixed with food and passed by trophallaxis, transferring information within the colony. This allows other ants to detect what task group ("e.g.", foraging or nest maintenance) other colony members belong to. In ant species with queen castes, workers begin to raise new queens in the colony when the dominant queen stops producing a specific pheromone. Some ants produce sounds by stridulation, using the gaster segments and their mandibles. Sounds may be used to communicate with colony members or with other species. Defence===. Ants attack and defend themselves by biting and, in many species, by stinging, often injecting or spraying chemicals like formic acid. Bullet ants ("Paraponera"), located in Central and South America, are considered to have the most painful sting of any insect, although it is usually not fatal to humans. This sting is given the highest rating on the Schmidt Sting Pain Index. The sting of Jack jumper ants can be fatal, and an antivenin has been developed. Fire ants, "Solenopsis" spp., are unique in having a poison sac containing piperidine alkaloids. Their stings are painful and can be dangerous to hypersensitive people. Trap-jaw ants of the genus "Odontomachus" are equipped with mandibles called trap-jaws, which snap shut faster than any other predatory appendages within the animal kingdom. One study of "Odontomachus bauri" recorded peak speeds of between 126 and 230 h (78 143 mph), with the jaws closing within 130 microseconds on average. The ants were also observed to use their jaws as a catapult to eject intruders or fling themselves backwards to escape a threat. Before the strike, the ant opens its mandibles extremely widely and locks them in this position by an internal mechanism. Energy is stored in a thick band of muscle and explosively released when triggered by the stimulation of sensory hairs on the inside of the mandibles. The mandibles also permit slow and fine movements for other tasks. Trap-jaws are also seen in the following genera: "Anochetus", "Orectognathus", and "Strumigenys", plus some members of the Dacetini tribe, which are viewed as examples of convergent evolution. In addition to defence against predators, ants need to protect their colonies from pathogens. Some worker ants maintain the hygiene of the colony and their activities include undertaking or "necrophory", the disposal of dead nest-mates. Oleic acid has been identified as the compound released by dead ants that triggers undertaking behaviour in "Atta mexicana". Nests may be protected from physical threats such as flooding and over-heating by elaborate nest architecture. Workers of "Cataulacus muticus", an arboreal species that lives in plant hollows, respond to flooding by drinking water inside the nest, and excreting it outside. Learning. Many animals can learn behaviours by imitation but ants may be the only group apart from mammals where interactive teaching has been observed. A knowledgeable forager of "Temnothorax albipennis" leads a naive nest-mate to newly discovered food by the excruciatingly slow process of tandem running. The follower obtains knowledge through its leading tutor. Both leader and follower are acutely sensitive to the progress of their partner with the leader slowing down when the follower lags, and speeding up when the follower gets too close. Controlled experiments with colonies of "Cerapachys biroi" suggest that individuals may choose nest roles based on their previous experience. An entire generation of identical workers was divided into two groups whose outcome in food foraging was controlled. One group was continually rewarded with prey, while it was made certain that the other failed. As a result, members of the successful group intensified their foraging attempts while the unsuccessful group ventured out less and less. A month later, the successful foragers continued in their role while the others moved to specialise in brood care. Nest construction. Complex nests are built by many ants, but other species are nomadic and do not build permanent structures. Ants may form subterranean nests or build them on trees. These nests can be found in the ground, under stones or logs, inside logs, hollow stems or even acorns. The materials used for construction include soil and plant matter, and ants carefully select their nest sites; "Temnothorax albipennis" will avoid sites with dead ants, as these may indicate the presence of pests or disease. They are quick to abandon established nests at the first sign of threats. The army ants of South America and the driver ants of Africa do not build permanent nests, but instead alternate between nomadism and stages where the workers form a temporary nest (bivouac) from their own bodies, by holding each other together. Weaver ant ("Oecophylla" spp.) workers build nests in trees by attaching leaves together, first pulling them together with bridges of workers and then inducing their larvae to produce silk as they are moved along the leaf edges. Similar forms of nest construction are seen in some species of "Polyrhachis". Food cultivation. Most ants are generalist predators, scavengers and indirect herbivores, but a few have evolved specialised ways of obtaining nutrition. Leafcutter ants ("Atta" and "Acromyrmex") feed exclusively on a fungus that grows only within their colonies. They continually collect leaves which are taken to the colony, cut into tiny pieces and placed in fungal gardens. Workers specialise in tasks according to their sizes. The largest ants cut stalks, smaller workers chew the leaves and the smallest tend the fungus. Leafcutter ants are sensitive enough to recognise the reaction of the fungus to different plant material, apparently detecting chemical signals from the fungus. If a particular type of leaf is toxic to the fungus the colony will no longer collect it. The ants feed on structures produced by the fungi called "gongylidia". Symbiotic bacteria on the exterior surface of the ants produce antibiotics that kill bacteria that may harm the fungi. Navigation. Foraging ants travel distances of up to from their nest and usually find their way back using scent trails. Some ants forage at night. Day foraging ants in hot and arid regions face death by desiccation, so the ability to find the shortest route back to the nest reduces that risk. Diurnal desert ants ("Cataglyphis fortis") use visual landmarks in combination with other cues to navigate. In the absence of visual landmarks, the closely related Sahara desert ant ("Cataglyphis bicolor") navigates by keeping track of direction as well as distance travelled, like an internal pedometer that counts how many steps they take in each direction. They integrate this information to find the shortest route back to their nest. Several species of ants are able to use the Earth's magnetic field. Ants' compound eyes have specialised cells that detect polarised light from the Sun, which is used to determine direction. Locomotion. Worker ants do not have wings and reproductive females lose their wings after their mating flights in order to begin their colonies. Therefore, unlike their wasp ancestors, most ants travel by walking. Some species are capable of leaping. For example, Jerdon's jumping ant ("Harpegnathos saltator") is able to jump by synchronising the action of its mid and hind pairs of legs. There are several species of gliding ant including "Cephalotes atratus"; this may be a common trait among most arboreal ants. Ants with this ability are able to control the direction of their descent while falling. Other species of ants can form chains to bridge gaps over water, underground, or through spaces in vegetation. Some species also form floating rafts that help them survive floods. These rafts may also have a role in allowing ants to colonise islands. "Polyrhachis sokolova", a species of ant found in Australian mangrove swamps, can swim and live in underwater nests. Since they lack gills, they breathe in trapped pockets of air in the submerged nests. Cooperation and competition. Not all ants have the same kind of societies. The Australian bulldog ants are among the biggest and most basal (primitive) of ants. Like virtually all ants they are eusocial, but their social behaviour is poorly developed compared to other species. Each individual hunts alone, using its large eyes instead of its chemical senses to find prey. Some species (such as "Tetramorium caespitum") attack and take over neighbouring ant colonies. Others are less expansionist but just as aggressive; they invade colonies to steal eggs or larvae, which they either eat or raise as workers slaves. Extreme specialists among these slave-raiding ants, such as the Amazon ants, are incapable of feeding themselves and need captured workers to survive. Ants identify kin and nestmates through their scent, which comes from hydrocarbon-laced secretions that coat their exoskeletons. If an ant is separated from its original colony, it will eventually lose the colony scent. Any ant that enters a colony without a matching scent will be attacked. Parasitic ant species enter the colonies of host ants and establish themselves as social parasites; species like "Strumigenys xenos" are entirely parasitic and do not have workers, but instead rely on the food gathered by their "Strumigenys perplexa" hosts. This form of parasitism is seen across many ant genera, but the parasitic ant is usually a species that is closely related to its host. A variety of methods are employed to enter the nest of the host ant. A parasitic queen can enter the host nest before the first brood has hatched, establishing herself prior to development of a colony scent. Other species use pheromones to confuse the host ants or to trick them into carrying the parasitic queen into the nest. Some simply fight their way into the nest. A conflict between the sexes of a species is seen in some species of ants with the reproductives apparently competing to produce offspring that are as closely related to them as possible. The most extreme form involves the production of clonal offspring. An extreme of sexual conflict is seen in "Wasmannia auropunctata", where the queens produce diploid daughters by thelytokous parthenogenesis and males produce clones by a process where a diploid egg loses its maternal contribution to produce haploid males that are clones of the father. Relationships with other organisms. The spider "Myrmarachne plataleoides" (here a female) mimics weaver ants to avoid predators. Ants form symbiotic associations with a range of species, including other ant species, other insects, plants, and fungi. They are preyed on by many animals and even certain fungi. Some arthropod species spend part of their lives within ant nests, either preying on ants, their larvae and eggs, consuming the ants' food stores, or avoiding predators. These inquilines can bear a close resemblance to ants. The nature of this ant mimicry (myrmecomorphy) varies, with some cases involving Batesian mimicry, where the mimic reduces the risk of predation. Others show Wasmannian mimicry, a form of mimicry seen only in inquilines. Aphids and other hemipteran insects secrete a sweet liquid called honeydew when they feed on plant sap. The sugars in honeydew are a high-energy food source, which many ant species collect. In some cases the aphids secrete the honeydew in response to the ants' tapping them with their antennae. The ants in turn keep predators away and will move the aphids between feeding locations. On migrating to a new area, many colonies will take the aphids with them, to ensure a continued supply of honeydew. Ants also tend mealybugs to harvest their honeydew. Mealybugs can become a serious pest of pineapples if ants are present to protect mealybugs from their natural enemies. Myrmecophilous (ant-loving) caterpillars of the family Lycaenidae (e.g., blues, coppers, or hairstreaks) are herded by the ants, led to feeding areas in the daytime, and brought inside the ants' nest at night. The caterpillars have a gland which secretes honeydew when the ants massage them. Some caterpillars produce vibrations and sounds that are perceived by the ants. Other caterpillars have evolved from ant-loving to ant-eating: these myrmecophagous caterpillars secrete a pheromone that makes the ants act as if the caterpillar is one of their own larvae. The caterpillar is then taken into the ants' nest where it feeds on the ant larvae. Fungus-growing ants that make up the tribe Attini, including leafcutter ants, cultivate certain species of fungus in the "Leucoagaricus" or "Leucocoprinus" genera of the Agaricaceae family. In this ant-fungus mutualism, both species depend on each other for survival. The ant "Allomerus decemarticulatus" has evolved a three-way association with the host plant "Hirtella physophora" (Chrysobalanaceae), and a sticky fungus which is used to trap their insect prey. Lemon ants make devil's gardens by killing surrounding plants with their stings and leaving a pure patch of lemon ant trees ("Duroia hirsuta"). This modification of the forest provides the ants with more nesting sites inside the stems of the "Duroia" trees. Some trees have extrafloral nectaries that provide food for ants, which in turn protect the plant from herbivorous insects. Species like the bullhorn acacia ("Acacia cornigera") in Central America have hollow thorns that house colonies of stinging ants ("Pseudomyrmex ferruginea") that defend the tree against insects, browsing mammals, and epiphytic vines. Isotopic labelling studies suggest that plants also obtain nitrogen from the symbiotic ants. In return, the ants obtain food from protein-lipid Beltian bodies. Another example of this type of ectosymbiosis comes from the "Macaranga" tree, which has stems adapted to house colonies of "Crematogaster" ants. Many tropical tree species have seeds that are dispersed by ants. Seed dispersal by ants or myrmecochory is widespread particularly in Africa and Australia. Some plants in fire-prone grassland systems are particularly dependent on ants for their survival and dispersal. Many ant-dispersed seeds have special external structures, elaiosomes, that are sought after by ants as food. A convergence, possibly a form of mimicry, is seen in the eggs of stick insects. They have an edible elaiosome-like structure and are taken into the ant nest where the young hatch. Ants prey on and obtain food from a number of social insects including other ants. Some species specialise in preying on termites ("Megaponera" and "Termitopone") while a few Cerapachyinae prey on other ants. Some termites form associations with certain ant species to keep away other predatory ant species.The tropical wasp "Mischocyttarus drewseni" coats the pedicel of its nest with an ant-repellant chemical. It is suggested that many tropical wasps may build their nests in trees and cover them to protect themselves from ants. Stingless bees ("Trigona" and "Melipona") use chemical defences against ants. Flies in the Old World genus "Bengalia" (Calliphoridae) prey on ants and are kleptoparasites, snatching prey or brood from the mandibles of adult ants. Wingless and legless females of the Malaysian phorid fly ("Vestigipoda myrmolarvoidea") live in the nests of ants of the genus "Aenictus" and are cared for by the ants. The fungus "Cordyceps" infects ants, causing them to climb up plants and sink their mandibles into plant tissue. The fungus kills the ant, grows on its remains, and produces a fruiting body. It appears that the fungus alters the behaviour of the ant to help disperse its spores. Strepsipteran parasites also manipulate their ant host to climb grass stems, to help the parasite find mates. A nematode ("Myrmeconema neotropicum") that infects canopy ants ("Cephalotes atratus") causes the black coloured gasters of workers to turn red. The parasite also alters the behaviour of the ant, and makes them carry their gasters high. The conspicuous red gasters are mistaken by birds for ripe fruits such as "Hyeronima alchorneoides" and eaten. The droppings of the bird are collected by other ants and fed to their young leading to the further spread of the nematode. South American poison dart frogs in the genus "Dendrobates" feed mainly on ants, and the toxins in their skin may come from the ants. Several South American antbirds follow army ants to feed on the insects that are flushed from cover by the foraging ants. This behaviour was once considered mutualistic, but later studies show that it is instead kleptoparastic, with the birds stealing prey. Birds indulge in a peculiar behaviour called anting that is as yet not fully understood. Here birds rest on ant nests, or pick and drop ants onto their wings and feathers; this may remove ectoparasites. Anteaters, pangolins and several marsupial species in Australia have special adaptations for living on a diet of ants. These adaptations include long, sticky tongues to capture ants and strong claws to break into ant nests. Brown bears ("Ursus arctos") have been found to feed on ants, and about 12%, 16%, and 4% of their faecal volume in spring, summer, and autumn, respectively, is composed of ants. Relationship with humans. Ants perform many ecological roles that are beneficial to humans, including the suppression of pest populations and aeration of the soil. The use of weaver ants in citrus cultivation in southern China is considered one of the oldest known applications of biological control. On the other hand, ants can become nuisances when they invade buildings, or cause economic losses. In some parts of the world (mainly Africa and South America), large ants, especially army ants, are used as surgical sutures. The wound is pressed together and ants are applied along it. The ant seizes the edges of the wound in its mandibles and locks in place. The body is then cut off and the head and mandibles remain in place to close the wound. Some ants of the family Ponerinae have toxic venom and are of medical importance. The species include "Paraponera clavata" ("Tocandira") and "Dinoponera" spp. (false "Tocandira"s) of South America and the "Myrmecia" ants of Australia. In South Africa, ants are used to help harvest rooibos ("Aspalathus linearis"), which are small seeds used to make a herbal tea. The plant disperses its seeds widely, making manual collection difficult. Black ants collect and store these and other seeds in their nest, where humans can gather them "en masse". Up to half a pound (200 g) of seeds can be collected from one ant-heap. As food. Ants and their larvae are eaten in different parts of the world. The eggs of two species of ants are the basis for the dish in Mexico known as "escamoles". They are considered a form of insect caviar and can sell for as much as USD 40 per pound (USD 90 kg) because they are seasonal and hard to find. In the Colombian department of Santander, "hormigas culonas" (roughly interpreted as "large-bottomed ants") "Atta laevigata" are toasted alive and eaten. In areas of India, and throughout Burma and Thailand, a paste of the green weaver ant ("Oecophylla smaragdina") is served as a condiment with curry. Weaver ant eggs and larvae as well as the ants themselves may be used in a Thai salad, "yum" (ยำ), in a dish called "yum khai mod daeng" (ยำไข่มดแดง) or red ant egg salad, a dish that comes from the Issan or north-eastern region of Thailand. Saville-Kent, in the "Naturalist in Australia" wrote "Beauty, in the case of the green ant, is more than skin-deep. Their attractive, almost sweetmeat-like translucency possibly invited the first essays at their consumption by the human species". Mashed up in water, after the manner of lemon squash, "these ants form a pleasant acid drink which is held in high favor by the natives of North Queensland, and is even appreciated by many European palates". In his "First Summer in the Sierra", John Muir notes that the Digger Indians of California ate the tickly acid gasters of the large jet-black carpenter ants. The Mexican Indians eat the replete workers, or living honey-pots, of the honey ant ("Myrmecocystus"). As pests. Some ant species are considered pests, and because of the adaptive nature of ant colonies, eliminating the entire colony is nearly impossible. Pest management is therefore a matter of controlling local populations, instead of eliminating an entire colony, and most attempts at control are temporary solutions. Ants classified as pests include the pavement ant, yellow crazy ant, sugar ants, the Pharaoh ant, carpenter ants, Argentine ant, odorous house ants, red imported fire ant and European fire ant. Populations are controlled using insecticide baits, either in granule or liquid formulations. Bait is gathered by the ants as food and brought back to the nest where the poison is inadvertently spread to other colony members through trophallaxis. Boric acid and borax are often used as insecticides that are relatively safe for humans. Bait may be broadcast over a large area to control species like the red fire ant that occupy large areas. Nests of red fire ants may be destroyed by following the ants' trails back to the nest and then pouring boiling water into it to kill the queen. This works in about 60% of the mounds and requires about per mound. In science and technology. Myrmecologists study ants in the laboratory and in their natural conditions. Their complex and variable social structures have made ants ideal model organisms. Studies on ants have tested hypotheses in ecology, sociobiology and have been particularly important in examining the predictions of theories of kin selection and evolutionarily stable strategies. Ant colonies can be studied by rearing or temporarily maintaining them in formicaria, specially constructed glass framed enclosures. Individuals may be tracked for study by marking them with colours. The successful techniques used by ant colonies have been studied in computer science and robotics to produce distributed and fault-tolerant systems for solving problems. This area of biomimetics has led to studies of ant locomotion, search engines that make use of "foraging trails", fault-tolerant storage and networking algorithms. In culture. Ants have often been used in fables and children's stories to represent industriousness and cooperative effort. They are also mentioned in religious texts. In the Book of Proverbs in the Bible, ants are held up as a good example for humans for their hard work and cooperation. Aesop did the same in his fable The Ant and the Grasshopper. In parts of Africa, ants are considered to be the messengers of the gods. Ant bites are often said to have curative properties. The sting of some species of "Pseudomyrmex" is claimed to give fever relief. Some Native American mythology, such as the Hopi mythology, considers ants as the very first animals. Others use ant bites in initiation ceremonies as a test of endurance. Ant society has always fascinated humans and has been written about both humorously and seriously. Mark Twain wrote about ants in his "A Tramp Abroad". Some modern authors have used the example of the ants to comment on the relationship between society and the individual. Examples are Robert Frost in his poem "Departmental" and T. H. White in his fantasy novel "The Once and Future King". The plot in French entomologist and writer Bernard Werber's "Les Fourmis" science-fiction trilogy is divided between the worlds of ants and humans; ants and their behaviour is described using contemporary scientific knowledge. In more recent times, animated cartoons and 3D animated movies featuring ants have been produced include "Antz", "A Bug's Life", "The Ant Bully", "The Ant and the Aardvark", "Atom Ant", and there is a comic book superhero called Ant-Man. From the late 1950s through the late 1970s, ant farms were popular educational children's toys in the United States. Later versions use transparent gel instead of soil allowing greater visibility. In the early 1990s, the video game SimAnt, which simulated an ant colony, won the 1992 Codie award for "Best Simulation Program". Ants are also quite popular inspiration for many science-fiction creatures, such as the Formics of "Ender's Game", the Bugs of "Starship Troopers", the giant ants in the film "Them!", and ants mutated into super intelligence in "Phase IV". In strategy games, ant-based species often benefit from increased production rates due to their single-minded focus, such as the Klackons in the "Master of Orion" series of games or the ChCht in "Deadlock II". These characters are often credited with a hive mind, a common misconception about ant colonies.