The peacock butterfly has brownish-red wings, each with a single, large peacock-feather-like eyespot – used to scare predators. It rests with its wings closed, showing the almost black, well-camouflaged underside.
It is one of the commonest garden butterflies, found throughout lowland England and Wales. It is rarer in Scotland.
In May, after mating, females lay their eggs in batches of up to 500. After a week or two the caterpillars hatch and spin a communal web in which they live and feed. As they grow the caterpillars increasingly live in the open.
They pupate alone, and adults emerge from July. The main priority is to feed-up before the winter hibernation in dark crevices, sheds and tree holes. Adults emerge again in spring to mate and breed.
Peacock caterpillars are black, covered with short spines and speckled with white spots. They are usually found on stinging nettles. Extract taken from RSPB (UK).