ratio of word probabilities predicted from brain for window and butterfly

window	butterfly
top 10 words in brain distribution (in article): material wood build wall design structure construction size window type	top 10 words in brain distribution (in article): species plant city fruit grow state food house tree leaf
top 10 words in brain distribution (not in article): paint floor tree concrete brick space city shape leather manufacture	top 10 words in brain distribution (not in article): animal seed store build Unite street town home wild population
times more probable under window 30 20 10 6 4 2.5 1.25 1 1.25 2.5 4 6 10 20 30 times more probable under butterfly (words not in the model)
Pair of windows, Old Ship Church, Hingham, Massachusetts A window'" is an opening in a wall (or other solid and opaque surface) that allows the passage of light and, if not closed or sealed, air and sound. Windows are usually glazed or covered in some other transparent or translucent material. Windows are held in place by frames, which prevent them from collapsing in. Etymology. The word "Window" originates from the Old Norse ‘vindauga’, from ‘vindr – wind’ and ‘auga – eye’, i.e. "wind eye". In Norwegian Nynorsk and Icelandic the Old Norse form has survived to this day (in Icelandic only as a less used synonym to "gluggi"), while Swedish has kept it—mostly in dialects—as ‘vindöga’ (‘öga – eye’). Danish ‘vindue’ and Norwegian Bokmål ‘vindu’ however, have lost the direct link to ‘eye’, just like "window" has. The Danish (but not the Bokmål) word is pronounced fairly similar to "window". "Window" is first recorded in the early 13th century, and originally referred to an unglazed hole in a roof. "Window" replaced the Old English ‘eagþyrl’, which literally means ‘eye-hole,’ and ‘eagduru’ ‘eye-door’. Many Germanic languages however adopted the Latin word ‘fenestra’ to describe a window with glass, such as standard Swedish ‘fönster’, or German ‘Fenster’. The use of "window" in English is probably due to the Scandinavian influence on the English language by means of loanwords during the Viking Age. In English the word "fenester" was used as a parallel until the mid-1700s and "fenestration" is still used to describe the arrangement of windows within a façade. Types in history. Primitive windows were just holes. Later, windows were covered with animal hide, cloth, or wood. Shutters that could be opened and closed came next. Over time, windows were built that both protected the inhabitants from the elements and transmitted light: mullioned glass windows, which joined multiple small pieces of glass with leading, paper windows, flattened pieces of translucent animal horn, and plates of thinly sliced marble. The Romans were the first to use glass for windows. In Alexandria ca. 100 AD, cast glass windows, albeit with poor optical properties, began to appear. Mullioned glass windows were the windows of choice among European well-to-do, whereas paper windows were economical and widely used in ancient China, Korea, Japan. In England, glass became common in the windows of ordinary homes only in the early 17th century whereas windows made up of panes of flattened animal horn were used as early as the 14th century in Northern Britain. Modern-style floor-to-ceiling windows became possible only after the industrial glass making process was perfected. Evidence of glass window panes in Italy dates back nearly 3000 years. Double-hung sash window. This sash window is the traditional style of window in the USA, and many other places that were formerly colonized by the UK, with two parts (sashes) that overlap slightly and slide up and down inside the frame. The two parts are not necessarily the same size. Nowadays, most new double-hung sash windows use spring balances to support the sashes, but traditionally, counterweights held in boxes either side of the window were used. These were and are attached to the sashes using pulleys of either braided cord or, later, purpose-made chain. Double-hung sash windows were traditionally often fitted with shutters. Sash windows may be fitted with simplex hinges which allow the window to be locked into hinges on one side, while the rope on the other side is detached, allowing the window to be opened for escape or cleaning. Single-hung sash window. One sash is movable (usually the bottom one) and the other fixed. This is the earlier form of sliding sash window, and is obviously also cheaper. Horizontal sliding sash window. Has two or more sashes that overlap slightly but slide horizontally within the frame. In the UK, these are sometimes called "Yorkshire" sash windows, presumably because of their traditional use in that county. Casement window. A window with a hinged sash that swings in or out like a door comprising either a side-hung, top-hung (also called "awning window"; see below), or occasionally bottom-hung sash or a combination of these types, sometimes with fixed panels on one or more sides of the sash. In the USA these are usually opened using a crank, but in Europe they tend to use projection friction stays and espagnolette locking. Formerly, plain hinges were used with a casement stay. Handing applies to casement windows to determine direction of swing. Awning window. An awning window is a casement window that is hung horizontally, hinged on top, so that it swings outward like an awning. Hopper window. A hopper window is a bottom hung casement window that opens similar to a draw bridge typically opening to the outside. Tilt and slide. A window (more usually a door-sized window) where the sash tilts inwards at the top and then slides horizontally behind the fixed pane. Tilt and turn. A window which can either tilt inwards at the top, or can open inwards hinged at the side. Transom window. A window above a door; if an exterior door the transom window is often fixed, if an interior door it can often open either by hinges at top or bottom, or can rotate about hinges at the middle of its sides. It provided ventilation before forced air heating and cooling. A transom may also be known as a fanlight, especially if it is fan-shaped, particularly in the British Isles. Jalousie window. Also known as a louvered window, the jalousie window is comprised of parallel slats of glass or acrylic that open and close like a Venetian blind, usually using a crank or a lever. They are used extensively in tropical architecture. A jalousie door is a door with a jalousie window. Clerestory window. A vertical window set in a roof structure or high in a wall, used for daylighting. Skylight. A flat or sloped window used for daylighting, built into a roof structure that is out of reach. Roof Window. A sloped window used for daylighting, built into a roof structure that is within reach. Roof Lantern or Cupola. A roof lantern is a multi-paned glass structure, resembling a small building, built on a roof for day or moon light. Sometimes includes an additional clerestory. May also be called a cupola. Bay window. A multi-panel window, with at least three panels set at different angles to create a protrusion from the wall line.it is commonly used in cold country where snow often falls. The panels are thus set in three different directions,from where a person would have a view from the interior of a building. Oriel window. A window with many panels. It is most often seen in the typical Tudor-style house and monasterie. An oriel window projects from the wall and does not extend to the ground. Oriel windows originated as a form of porch. They are often supported by brackets or corbels. Buildings in the Gothic Revival style often have oriell windows. Thermal window. Thermal, or Diocletian, windows are large semicircular windows (or niches) which are usually divided into three lights (window compartments) by two vertical mullions. The central compartment is often wider than the two side lights on either side of it. Fixed window. A window that cannot be opened, whose function is limited to allowing light to enter. Clerestory windows are often fixed. Transom windows may be fixed or operable. Picture window. A very large fixed window in a wall, typically without glazing bars, or glazed with only perfunctory glazing bars near the edge of the window. Picture windows are intended to provide an unimpeded view, as if framing a picture. Multi-lit window /divided-lite window. A window glazed with small panes of glass separated by wooden or lead "glazing bars", or "muntins", arranged in a decorative "glazing pattern" often dictated by the architectural style at use. Due to the historic unavailability of large panes of glass, this was the prevailing style of window until the beginning of the twentieth century, and is traditionally still used today. Emergency exit window /egress window. A window big enough and low enough so that occupants can escape through the opening in an emergency, such as a fire. In the United States, exact specifications for emergency windows in bedrooms are given in many building codes. Vehicles, such as buses and aircraft, frequently have emergency exit windows as well. Stained glass window. A window composed of pieces of colored glass, transparent or opaque, frequently portraying persons or scenes. Typically the glass in these windows is separated by lead glazing bars. Stained glass windows were popular in Victorian houses and some Wrightian houses, and are especially common in churches. French window. A French window, also known as a "French door" is really a type of door, but one which has one or more panes of glass set into the whole length of the door, meaning it also functions as a window. Super window. A popular term for highly insulating window with a heat loss so low it performs better than an insulated wall in winter, since the sunlight that it admits is greater than its heat loss over a 24 hour period. Technical terms. In insulated glass production, the term "lite" refers to a glass pane, several of which may be used to construct the final window product. For example, a sash unit, consisting of at least one sliding glass component, is typically composed of two lites, while a fixed window is composed of one lite. The terms "single-light", "double-light" etc refer to the number of these glass panes in a window. The lites in a window sash are divided horizontally and vertically by narrow strips of wood or metal called muntins. More substantial load bearing or structural vertical dividers are called mullions, with the corresponding horizontal dividers referred to as transoms. In the USA, the term "replacement window" means a framed window designed to slip inside the original window frame from the inside after the old sashes are removed. In Europe, however, it usually means a complete window including a replacement outer frame. The USA term "new construction window" means a window with a nailing fin designed to be inserted into a rough opening from the outside before applying siding and inside trim. A nailing fin is a projection on the outer frame of the window in the same plane as the glazing, which overlaps the prepared opening, and can thus be 'nailed' into place). In the UK and Europe, windows in new-build houses are usually fixed with long screws into expanding plastic plugs in the brickwork. A gap of up to 13mm is left around all four sides, and filled with expanding polyurethane foam. This makes the window fixing weatherproof but allows for expansion due to heat. A beam over the top of a window is known as the lintel or transom. In the USA, the NRFC Window Label lists the following terms: Window construction. Windows can be a significant source of heat transfer. Insulated glazing units therefore consist of two or more panes to reduce the heat transfer. Frame and sash construction. Frames and sashes can be made of the following materials: Composites may combine materials to obtain aesthetics of one material with the functional benefits of another. Glazing and filling. Low-emissivity coated panes reduce heat transfer by radiation, which, depending on which surface is coated, helps prevent heat loss (in cold climates) or heat gains (in warm climates). High thermal resistance can be obtained by evacuating or filling the insulated glazing units with gases such as argon or krypton, which reduces conductive heat transfer due to their low thermal conductivity. Performance of such units depends on good window seals and meticulous frame construction to prevent entry of air and loss of efficiency. Modern windows are usually glazed with one large sheet of glass per sash, while windows in the past were glazed with multiple panes separated by "glazing bars", or "muntins", due to the unavailability of large sheets of glass. Today, glazing bars tend to be decorative, separating windows into small panes of glass even though larger panes of glass are available, generally in a pattern dictated by the architectural style at use. Glazing bars are typically wooden, but occasionally lead glazing bars soldered in place are used for more intricate glazing patterns. Other construction details. Many windows have movable window coverings such as blinds or curtains to keep out light, provide additional insulation, or ensure privacy. Sun incidence angle. Historically, windows are designed with surfaces parallel to vertical building walls. Such a design allows considerable solar light and heat penetration due to the most commonly occurring incidence of sun angles. In passive solar building design, an extended eave is typically used to control the amount of solar light and heat entering the window(s). An alternate method would be to calculate a more optimum angle for mounting windows which accounts for summer sun load minimization, with consideration of the actual latitude of the particular building. An example where this process has been implemented is the Dakin Building, Brisbane, California; much of the fenestration has been designed to reflect summer heat load and assist in preventing summer interior over-illumination and glare, by designing window canting to achieve a near 45 degree angle. Solar window. Solar windows not only provide a clear view and illuminate rooms, but also use sunlight to efficiently help generate electricity for the building. Windows and religion. The symbolism of windows plays a part in the customs and traditions of certain religions.	A butterfly'" is an insect of the order Lepidoptera. Like all Lepidoptera, butterflies are notable for their unusual life cycle with a larval caterpillar stage, an inactive pupal stage, and a spectacular metamorphosis into a familiar and colourful winged adult form. Most species are day-flying so they regularly attract attention. The diverse patterns formed by their brightly coloured wings and their erratic yet graceful flight have made butterfly watching a hobby. Butterflies comprise the "true butterflies" (superfamily Papilionoidea), the "skippers" (superfamily Hesperioidea) and the "moth-butterflies" (superfamily Hedyloidea). Butterflies exhibit polymorphism, mimicry and aposematism. Some migrate over long distances. Some butterflies have evolved symbiotic and parasitic relationships with social insects such as ants. Butterflies are important economically as agents of pollination. In addition, a few species are pests, because they can damage domestic crops and trees in their larval stage. Culturally, butterflies are a popular motif in the visual and literary arts. The four-stage lifecycle. Unlike many insects, butterflies do not experience a nymph period, but instead go through a pupal stage which lies between the larva and the adult stage (the "imago"). Butterflies are termed as holometabolous insects, and go through complete metamorphosis. It is a popular belief that butterflies have very short life spans. However, butterflies in their adult stage can live from a week to nearly a year depending on the species. Many species have long larval life stages while others can remain dormant in their pupal or egg stages and thereby survive winters. Butterflies may have one or more broods per year. The number of generations per year varies from temperate to tropical regions with tropical regions showing a trend towards multivoltinism. Egg. Butterfly eggs consist of a hard-ridged outer layer of shell, called the "chorion". This is lined with a thin coating of wax which prevents the egg from drying out before the larva has had time to fully develop. Each egg contains a number of tiny funnel-shaped openings at one end, called "micropyles"; the purpose of these holes is to allow sperm to enter and fertilize the egg. Butterfly and moth eggs vary greatly in size between species, but they are all either spherical or ovate. Butterfly eggs are fixed to a leaf with a special glue which hardens rapidly. As it hardens it contracts, deforming the shape of the egg. This glue is easily seen surrounding the base of every egg forming a meniscus. The nature of the glue is unknown and is a suitable subject for research. The same glue is produced by a pupa to secure the setae of the cremaster. This glue is so hard that the silk pad, to which the setae are glued, cannot be separated. Eggs are usually laid on plants. Each species of butterfly has its own hostplant range and while some species of butterfly are restricted to just one species of plant, others use a range of plant species, often including members of a common family. The egg stage lasts a few weeks in most butterflies but eggs laid close to winter, especially in temperate regions, go through a "diapause" stage, and the hatching may take place only in spring. Other butterflies may lay their eggs in the spring and have them hatch in the summer. These butterflies are usually northern species (Mourning Cloak, Tortoiseshells) Caterpillars. Butterfly larvae, or caterpillars, consume plant leaves and spend practically all of their time in search of food. Although most caterpillars are herbivorous, a few species such as "Spalgis epius" and "Liphyra brassolis" are entomophagous (insect eating). Some larvae, especially those of the Lycaenidae, form mutual associations with ants. They communicate with the ants using vibrations that are transmitted through the substrate as well as using chemical signals. The ants provide some degree of protection to these larvae and they in turn gather honeydew secretions. Caterpillars mature through a series of stages called instars. Near the end of each instar, the larva undergoes a process called apolysis, in which the cuticle, a mixture of chitin and specialized proteins, is released from the epidermis and the epidermis begins to form a new cuticle beneath. At the end of each instar, the larva moults the old cuticle, and the new cuticle rapidly hardens and pigments. Development of butterfly wing patterns begins by the last larval instar. Butterfly caterpillars have three pairs of true legs from the thoracic segments and up to 6 pairs of prolegs arising from the abdominal segments. These prolegs have rings of tiny hooks called crochets that help them grip the substrate. Some caterpillars have the ability to inflate parts of their head to appear snake-like. Many have false eye-spots to enhance this effect. Some caterpillars have special structures called osmeteria which are everted to produce smelly chemicals. These are used in defense. Host plants often have toxic substances in them and caterpillars are able to sequester these substances and retain them into the adult stage. This helps making them unpalatable to birds and other predators. Such unpalatibility is advertised using bright red, orange, black or white warning colours. The toxic chemicals in plants are often evolved specifically to prevent them from being eaten by insects. Insects in turn develop countermeasures or make use of these toxins for their own survival. This "arms race" has led to the coevolution of insects and their host plants. Wing development. Wings or wing pads are not visible on the outside of the larva, but when larvae are dissected, tiny developing "wing disks" can be found on the second and third thoracic segments, in place of the spiracles that are apparent on abdominal segments. Wing disks develop in association with a trachea that runs along the base of the wing, and are surrounded by a thin "peripodial membrane", which is linked to the outer epidermis of the larva by a tiny duct. Wing disks are very small until the last larval instar, when they increase dramatically in size, are invaded by branching tracheae from the wing base that precede the formation of the wing veins, and begin to develop patterns associated with several landmarks of the wing. Near pupation, the wings are forced outside the epidermis under pressure from the hemolymph, and although they are initially quite flexible and fragile, by the time the pupa breaks free of the larval cuticle they have adhered tightly to the outer cuticle of the pupa (in obtect pupae). Within hours, the wings form a cuticle so hard and well-joined to the body that pupae can be picked up and handled without damage to the wings. Pupa. When the larva is fully grown, hormones such as prothoracicotropic hormone (PTTH) are produced. At this point the larva stops feeding and begins "wandering" in the quest of a suitable pupation site, often the underside of a leaf. The larva transforms into a pupa (or chrysalis) by anchoring itself to a substrate and moulting for the last time. The chrysalis is usually incapable of movement, although some species can rapidly move the abdominal segments or produce sounds to scare potential predators. The pupal transformation into a butterfly through metamorphosis has held great appeal to mankind. To transform from the miniature wings visible on the outside of the pupa into large structures usable for flight, the pupal wings undergo rapid mitosis and absorb a great deal of nutrients. If one wing is surgically removed early on, the other three will grow to a larger size. In the pupa, the wing forms a structure that becomes compressed from top to bottom and pleated from proximal to distal ends as it grows, so that it can rapidly be unfolded to its full adult size. Several boundaries seen in the adult color pattern are marked by changes in the expression of particular transcription factors in the early pupa. Adult or imago. The adult, sexually mature, stage of the insect is known as the imago. As Lepidoptera, butterflies have four wings that are covered with tiny scales (see photo). The fore and hindwings are not hooked together, permitting a more graceful flight. An adult butterfly has six legs, but in the nymphalids, the first pair is reduced. After it emerges from its pupal stage, a butterfly cannot fly until the wings are unfolded. A newly-emerged butterfly needs to spend some time inflating its wings with blood and letting them dry, during which time it is extremely vulnerable to predators. Some butterflies' wings may take up to three hours to dry while others take about one hour. Most butterflies and moths will excrete excess dye after hatching. This fluid may be white, red, orange, or in rare cases, blue. External morphology. Butterflies have two antennae, two compound eyes, and a proboscis. Adult butterflies have four wings: a forewing and hindwing on both the left and the right side of the body. The body is divided into three segments: the head, thorax, and the abdomen. They have two antennae, two compound eyes, and a proboscis. Scales. Butterflies are characterized by their scale-covered wings. The coloration of butterfly wings is created by minute scales. These scales are pigmented with melanins that give them blacks and browns, but blues, greens, reds and iridescence are usually created not by pigments but the microstructure of the scales. This structural coloration is the result of coherent scattering of light by the photonic crystal nature of the scales. The scales cling somewhat loosely to the wing and come off easily without harming the butterfly. Polymorphism. Many adult butterflies exhibit polymorphism, showing differences in appearance. These variations include geographic variants and seasonal forms. In addition many species have females in multiple forms, often with mimetic forms. Sexual dimorphism in coloration and appearance is widespread in butterflies. In addition many species show sexual dimorphism in the patterns of ultraviolet reflectivity, while otherwise appearing identical to the unaided human eye. Most of the butterflies have a sex-determination system that is represented as ZW with females being the heterogametic sex (ZW) and males homogametic (ZZ). Genetic abnormalities such as gynandromorphy also occur from time to time. In addition many butterflies are infected by "Wolbachia" and infection by the bacteria can lead to the conversion of males into females or the selective killing of males in the egg stage. Mimicry. Batesian and Mullerian mimicry in butterflies is common. Batesian mimics imitate other species to enjoy the protection of an attribute they do not share, aposematism in this case. The Common Mormon of India has female morphs which imitate the unpalatable red-bodied swallowtails, the Common Rose and the Crimson Rose. Mullerian mimicry occurs when aposematic species evolve to resemble each other, presumably to reduce predator sampling rates, the Heliconius butterflies from the Americas being a good example. Wing markings called eyespots are present in some species; these may have an automimicry role for some species. In others, the function may be intraspecies communication, such as mate attraction. In several cases, however, the function of butterfly eyespots is not clear, and may be an evolutionary anomaly related to the relative elasticity of the genes that encode the spots. Seasonal polyphenism. div name="wet-dry forms" Many of the tropical butterflies have distinctive seasonal forms. This phenomenon is termed "seasonal polyphenism" and the seasonal forms of the butterflies are called the dry-season and wet-season forms. How the season affects the genetic expression of patterns is still a subject of research. Experimental modification by ecdysone hormone treatment has demonstrated that it is possible to control the continuum of expression of variation between the wet and dry-season forms. The dry-season forms are usually more cryptic and it has been suggested that the protection offered may be an adaptation. Some also show greater dark colours in the wet-season form which may have thermoregulatory advantages by increasing ability to absorb solar radiation. Habits. Butterflies feed primarily on nectar from flowers. Some also derive nourishment from pollen, tree sap, rotting fruit, dung, and dissolved minerals in wet sand or dirt. Butterflies are important as pollinators for some species of plants although in general they do not carry as much pollen load as the Hymenoptera. They are however capable of moving pollen over greater distances. Within the Lepidoptera, the Hawkmoths and the Noctuidae are dominant as pollinators. As adults, butterflies consume only liquids and these are sucked by means of their proboscis. They feed on nectar from flowers and also sip water from damp patches. This they do for water, for energy from sugars in nectar and for sodium and other minerals which are vital for their reproduction. Several species of butterflies need more sodium than provided by nectar. They are attracted to sodium in salt and they sometimes land on people, attracted by human sweat. Besides damp patches, some butterflies also visit dung, rotting fruit or carcasses to obtain minerals and nutrients. In many species, this Mud-puddling behaviour is restricted to the males and studies have suggested that the nutrients collected are provided as a nuptial gift along with the spermatophore during mating. Butterflies sense the air for scents, wind and nectar using their antennae. The antennae come in various shapes and colours. The hesperids have a pointed angle or hook to the antennae, while most other families show knobbed antennae. The antennae are richly covered with sensillae. A butterfly's sense of taste is coordinated by chemoreceptors on the tarsi, which work only on contact, and are used to determine whether an egg-laying insect's offspring will be able to feed on a leaf before eggs are laid on it. Many butterflies use chemical signals, pheromones, and specialized scent scales (androconia) and other structures (coremata or 'Hair pencils' in the Danaidae) are developed in some species. Vision is well developed in butterflies and most species are sensitive to the ultraviolet spectrum. Many species show sexual dimorphism in the patterns of UV reflective patches. Color vision may be widespread but has been demonstrated in only a few species. Some butterflies have organs of hearing and some species are also known to make stridulatory and clicking sounds. Many butterflies, such as the Monarch butterfly, are migratory and capable of long distance flights. They migrate during the day and use the sun to orient themselves. They also perceive polarized light and use it for orientation when the sun is hidden. Many species of butterfly maintain territories and actively chase other species or individuals that may stray into them. Some species will bask or perch on chosen perches. The flight styles of butterflies are often characteristic and some species have courtship flight displays. Basking is an activity which is more common in the cooler hours of the morning. Many species will orient themselves to gather heat from the sun. Some species have evolved dark wingbases to help in gathering more heat and this is especially evident in alpine forms. Flight. Like many other members of the insect world, the lift generated by butterflies is more than what can be accounted for by steady-state, non-transitory aerodynamics. Studies using "Vanessa atalanta" in a windtunnel show that they use a wide variety of aerodynamic mechanisms to generate force. These include wake capture, vortices at the wing edge, rotational mechanisms and Weis-Fogh 'clap-and-fling' mechanisms. The butterflies were also able to change from one mode to another rapidly. (See also Insect flight) Migration. Many butterflies migrate over long distances. Particularly famous migrations being those of the Monarch butterfly from Mexico to North America, a distance of about 4,000 to 4,800 kilometres (2500-3000 miles). Other well known migratory species include the Painted Lady and several of the Danaine butterflies. Spectacular and large scale migrations associated with the Monsoons are seen in peninsular India. Migrations have been studied in more recent times using wing tags and also using stable hydrogen isotopes. Butterflies have been shown to navigate using time compensated sun compasses. They can see polarized light and therefore orient even in cloudy conditions. The polarized light in the region close to the ultraviolet spectrum is suggested to be particularly important. It is suggested that most migratory butterflies are those that belong to semi-arid areas where breeding seasons are short. The life-histories of their host plants also influence the strategies of the butterflies. Defense. Butterflies are threatened in their early stages by parasitoids and in all stages by predators, diseases and environmental factors. They protect themselves by a variety of means. Chemical defenses are widespread and are mostly based on chemicals of plant origin. In many cases the plants themselves evolved these toxic substances as protection against herbivores. Butterflies have evolved mechanisms to sequester these plant toxins and use them instead in their own defense. These defense mechanisms are effective only if they are also well advertised and this has led to the evolution of bright colours in unpalatable butterflies. This signal may be mimicked by other butterflies. These mimetic forms are usually restricted to the females. Cryptic coloration is found in many butterflies. Some like the oakleaf butterfly are remarkable imitations of leaves. As caterpillars, many defend themselves by freezing and appearing like sticks or branches. Some papilionid caterpillars resemble bird dropping in their early instars. Some caterpillars have hairs and bristly structures that provide protection while others are gregarious and form dense aggregations. Some species also form associations with ants and gain their protection (See Myrmecophile). Behavioural defenses include perching and wing positions to avoid being conspicuous. Some female Nymphalid butterflies are known to guard their eggs from parasitoid wasps. Eyespots and tails are found in many lycaenid butterflies and these divert the attention of predators from the more vital head region. An alternative theory is that these cause ambush predators such as spiders to approach from the wrong end and allow for early visual detection. A butterfly's hind wings are thought to allow the butterfly to take, swift, tight turns to evade predators. Notable species. There are between 15,000 and 20,000 species of butterflies worldwide. Some well known species from around the world include: Art. Artistic depictions of butterflies have been used in many cultures including Egyptian hieroglyphs 3500 years ago. Today, butterflies are widely used in various objects of art and jewelry: mounted in frame, embedded in resin, displayed in bottles, laminated in paper, and used in some mixed media artworks and furnishings. Butterflies have also inspired the "butterfly fairy" as an art and fictional character. Symbolism. According to the “Butterflies” chapter in by Lafcadio Hearn, a butterfly is seen as the personification of a person's soul; whether they be living, dying, or already dead. One Japanese superstition says that if a butterfly enters your guestroom and perches behind the bamboo screen, the person whom you most love is coming to see you. However, large numbers of butterflies are viewed as bad omens. When Taira no Masakado was secretly preparing for his famous revolt, there appeared in Kyoto so vast a swarm of butterflies that the people were frightened — -thinking the apparition to be a portent of coming evil. The Russian word for "butterfly", бабочка ("bábochka"), also means "bow tie". It is a diminutive of "baba" or "babka" ("woman, grandmother, cake", whence also "babushka"= "grandmother". The Ancient Greek word for "butterfly" is ψυχή ("psȳchē"), which primarily means "soul", "mind". According to Mircea Eliade's "Encyclopedia of Religion", some of the Nagas of Manipur trace their ancestry from a butterfly. In Chinese culture two butterflies flying together are a symbol of love. Also a famous Chinese folk story called Butterfly Lovers. The Taoist philosopher Zhuangzi once had a dream of being a butterfly flying without care about humanity, however when he woke up and realized it was just a dream, he thought to himself "Was I before a man who dreamt about being a butterfly, or am I now a butterfly who dreams about being a man?" In some old cultures, butterflies also symbolize rebirth into a new life after being inside a cocoon for a period of time. Jose Rizal delivered a speech in 1884 in a banquet and mentioned "the Oriental chrysalis... is about to leave its cocoon" comparing the emergence of a "new Philippines" with that of butterfly metamorphosis. He has also often used the butterfly imagery in his poems and other writings to express the Spanish Colonial Filipinos' longing for liberty. Much later, in a letter to Ferdinand Blumentritt, Rizal compared his life in exile to a weary butterfly with sun-burnt wings. Some people say that when a butterfly lands on you it means good luck. However, in Devonshire, people would traditionally rush around to kill the first butterfly of the year that they see, or else face a year of bad luck. Also, in the Philippines, a lingering black butterfly or moth in the house is taken to mean that someone in the family has died or will soon die. The idiom "butterflies in the stomach" is used to describe a state of nervousness. Technological inspiration. Researches on the wing structure of Palawan Birdwing butterflies led to new wide wingspan kite and aircraft designs. Studies on the reflection and scattering of light by the scales on wings of swallowtail butterflies led to the innovation of more efficient light-emitting diodes. The structural coloration of butterflies is inspiring nanotechnology research to produce paints that do not use toxic pigments and in the development of new display technologies. Furthermore, the discoloration and health of butterflies in butterfly farms, is now being studied for use as indicators of air quality in several cities.