This family comprises about 11,000 species worldwide. Thirty-two species have been recorded from the British Isles, of which 29 are resident, five of these also being migrants. Another is a scarce immigrant, one a suspected immigrant and the status of the other is uncertain.
The subfamily Arctiinae includes the tiger and ermine moths. Tiger moths are boldly striped and banded, in some cases a reminder to predators that they are poisonous. Despite their size and bright colours, the patterns are often highly cryptic, making the moths hard to see when at rest in vegetation. The ermine moths are so-called because their wings are usually whitish, with black flecks or spots reminiscent of the ermine robes of dignitaries. The Lithosiinae are much slimmer, and often rather plain. Some of the smaller species could initially be mistaken for micro-moths, but they show relatively little variation and once known are easily recognised. They are named footman moths because many have long, narrow forewings and rest with them held over their back or wrapped around the body, bearing a resemblance to the long, stiff coats worn by the eponymous Victorian servants.
Many of the Arctidae do not feed, but most come to light-traps and some fly by day. The larvae are hairy, especially those of some of the tigers and ermines, but their hairs do not normally cause skin irritation. Larvae of the Arctiinae generally feed on herbaceous plants, whereas those of the lithosiinae feed mainly on lichens and algae growing on tress, rocks and walls, in dense low vegetation or on the ground. Pupation usually occurs in a cocoon formed above ground, either in a crevice, under bark or among low vegetation. (Taken from Waring and Townsend’s Field Guide to the Moths of Great Britain and Ireland)