This family comprises over 2,500 species, with representatives throughout the world. Twenty-seven have been found in the British Isles. Of these, 21 are certainly resident, one has not been seen since 1938 and one is a transitory resident, currently known from a single site. The remaining four are rare migrants.
The Notodontinae are furry, thick-bodied moths, in many cases with rather long, tapering forewings, which are normally held quite close to the body at rest. The trailing edge of the forewings of some of the species have prominent projections which are raised over the back when the moth is resting with its wings closed, hence the common name for the group. The adults are unable to feed, and are seldom seen by day, but the males especially come readily to light-traps. The antennae are relatively long and obvious in both sexes, and in most species are feathered in the male. The wing markings are subtle and cryptic, with a preponderance of brown, grey and white, often in beautifully textured patterns, which help them blend with bark and dead leaves. Variation is not usually great, and is largely confined to the ground-colour or the intensity of the dark markings.
The larvae are often striking, and raise both the head and tail end when threatened. Some have prominent lobe-like projections on their backs, or two extended ‘tails’. In the case of the Puss Moth, a red whip-like is produced from each tail, as an extra deterrent to would-be predators. The Puss Moth and the kittens are probably so-named because the young larvae have two ear-like projections just behind the head, making them appear rather cat-like from behind (although the adults are partricularly furry also). Prominent and kitten larvae feed on the foliage of trees and shrubs, resting on the foodplant when not feeding. The majority leave the foodplant to pupate below it, usually in the earth or among leaf litter, or in a hard cocoon on the trunk. The largest species have one generation a year. Some of the smaller species fit two generations into the year in the south, but in northern Britain they grow more slowly and complete only one.
(Taken from Waring and Townsend’s Field Guide to the Moths of Great Britain and Ireland)