Eye-spots may be a form of mimicry: the spot looks like the eye of a larger animal. Its function may be to draw a predator's attention away from the most vulnerable body parts; or to look like an unpleasant or dangerous animal.
There is evidence that eyespots in butterflies are anti-predator defences. Some are deimatic displays to distract, startle or scare off predators, or at least to deflect attacks away from vital body parts. Butterfly eyespots may also play a role in mate recognition and sexual selection, like the eyespots on larger organisms.
- Stevens, Martin (2005). "The role of eyespots as anti-predator mechanisms, principally demonstrated in the Lepidoptera". Biological Reviews. 80 (4): 573–588. doi:10.1017/S1464793105006810. PMID 16221330.
- Stevens, Martin & Ruxton, Graeme D. 2014. Do animal eyespots really mimic eyes? Current Zoology 60, 1, p26. 
- Blest A.D. 1957. The function of eyespot patterns in the Lepidoptera. Behavour 11, 209–255.
- Vallin A.; et al. (2005). "Prey survival by predator intimidation: an experimental study of peacock butterfly defence against blue tits". Proceedings Royal Society: Biological Sciences. 272 (1569): 1203–1207. doi:10.1098/rspb.2004.3034.
- Costanzo K. & Monteiro A. (2006). "The use of chemical and visual cues in female choice in the butterfly Bicyclus anynana". Proceedings Royal Society: Biological Sciences. 274: 845–851. doi:10.1098/rspb.2006.3729.
- "Female butterflies chase males when it's cool". Sify.