A worldwide pest of homes, shops, factories, catering establishments and rubbish tips. The adults are attracted to, and breed in, decaying animal and vegetable waste. The House fly is a major health risk: a carrier of a large number of disease organisms, e.g. Salmonella food poisoning and infantile diarrhoea. Active during the day and resting at night, preferring projecting edges high up in rooms as alighting surfaces.