The wingspan of the peacock butterfly reaches 6 centimetres. It has large wings, with reddish-brown colours above, and each wing is decorated with a big eye-like spot at the end. The underside is almost black, providing excellent camouflage when the insect is hibernating. The caterpillar is up to 45 millimetres long. It is black with small white spots and yellow abdominal legs and has 11 pairs of thick prickles.
Inhabiting open landscapes, gardens, parks and other flowery places, the peacock butterfly is found throughout Europe, except the far north.
This diurnal butterfly is visible from late spring to late autumn. It breeds twice per year, laying its eggs on nettle leaves or, rarely, on hop leaves, on which the hatched caterpillars feed. The caterpillars spend almost their entire lives on the leaves, living together in nests that they weave from web thread. This protects them from birds, which rarely attack groups of caterpillars, although they will eagerly eat individuals. The eye-like wing spots of the adult also provide protection by startling potential enemies when suddenly exposed.