Common in and around bird nests and farm buildings throughout the British Isles and on sea cliffs on St Kilda. In Hampshire probably common but under-recorded throughout, and increased recording activity on the Isle of Wight in recent years has revealed it to be widespread. Wingspan 13-20 mm. Similar to
M. obviella, but lateral dark margin of head wider (MBGBI Vol 2). Larva feeds on dead animals, animal waste, owl pellets, detritus in bird nests and bird guano, living within a silken tube or tent.