When full grown, maggots wander from the breeding site in search of a place to pupate. Although flies most often are a nuisance during the warm season, indoor overwintering is common with cluster flies and face flies. The adults spend the winter in homes or other protected sites but do not reproduce during this time. Blow fly maggots feed on garbage. They occasionally can be found in homes that are near a carcass of a dead squirrel, rodent or bird they have wandered from.
Blow flies breed most commonly on decayed carcasses and droppings of dogs or other pets.
The adult blow fly is also attracted to gas leaks. House fly and life cycle. House flies generally are gray, with the thorax marked with broad dark stripes. Most often there is some yellow coloring along the sides, which differentiates them from face flies. House flies usually are found where humans are present.