Common in oak woodland, birch woodland, scrub and hedgerows throughout much of the British Isles, but not in the Highlands or Islands of Scotland. In Hampshire and on the Isle of Wight widespread and common. Wingspan male 26-30 mm, female 15-20 mm. Males are frequent at light in spring, and are often encountered during the day resting on oak trunks. The female is flightless with greatly reduced wings (brachypterous) and is not so often seen. The species is very variable, ranging from pale to dark grey, sometimes almost black, and commonly features as an ID request on moth forums, being confused as a pyralid. Larva polyphagous on many deciduous trees and shrubs, including Oak, Beech, Hornbeam, Birch, Willow, Poplar, Hazel, Acer, Prunus and Rubus, usually feeding between leaves spun together with silk, over-wintering as a pupa.