<<An eyespot (sometimes ocellus) is an eye-like marking. They are found in butterflies, reptiles, cats, birds and fish. Eyespots may be a form of mimicry in which a spot on the body of an animal resembles an eye of a different animal to deceive potential predator
or prey species
; a form of self-mimicry, to draw a predator's attention away from the most vulnerable body parts; or to appear as an inedible or dangerous animal. In larger animals, eyespots may play a role in intraspecies communication or courtship. Eyespots are not necessarily adaptations, but may in some cases be spandrels, accidental artefacts of pattern formation.
Some members of the cat family Felidae, such as the leopard cat and leopard, have ocelli, white circular markings on the backs of the ears. Ocelli serve social functions, such as signaling to kittens, and communicating the cat's mental state to conspecifics in the gloom of dense forest or in tall grass.
The eye-like markings in some butterflies and moths, like the Bicyclus anynana, and certain other insects, as well as the Sunbittern (a bird) do not seem to serve only a mimicry function. In some other cases, the evolutionary function of such spots is also not understood. There is evidence that eyespots in butterflies are antipredator adaptations, either in deimatic displays to distract, startle or scare off predators, or to deflect attacks away from vital body parts. Butterfly eyespots may also play a role in mate recognition and sexual selection.
Some species of caterpillar, such as many hawkmoths (Sphingidae), have eyespots on their anterior abdominal segments. When alarmed, they retract the head and the thoracic segments into the body, leaving the apparently threatening large eyes at the front of the visible part of the body.
Many butterflies such as the blues (Lycaenidae) have filamentous "tails" at the ends of their wings and nearby patterns of markings on the wings, which combine to create a "false head". This misdirects predators such as birds and jumping spiders (Salticidae). Spectacular examples occur in the hairstreak butterflies; when perching on a twig or flower, they commonly do so upside down and shift their rear wings repeatedly, causing antenna-like movements of the "tails" on their wings. Studies of rear-wing damage support the hypothesis that this strategy is effective in deflecting attacks from the insect's head.
Some reptiles, such as the sand lizard of Europe, have eyespots; in the sand lizard's case, there is a row of spots along the back, and a row on each side.
Male birds of some species, such as the peacock, have conspicuous eyespots in their plumage, used to signal their quality to sexually selecting females. The number of eyespots in a peacock's train predicts his mating success; when a peacock's train is experimentally pruned, females lose interest. Several species of pygmy owl bear false eyes on the back of the head, misleading predators into reacting as though they were the subject of an aggressive stare.
Some fish have eyespots. The foureye butterflyfish gets its name from a large and conspicuous eyespot on each side of the body near the tail. A black vertical bar on the head runs through the true eye, making it hard to see. This may deceive predators into attacking the tail rather than the more vulnerable head, and about the fish's likely direction of travel: in other words, the eyespot is an example of self-mimicry. For the same reason, many juvenile fish display eyespots that disappear during their adult phase.>>