Eggs are laid in clumps, and a female may lay hundreds in a lifetime. Despite what is commonly thought, meat does not need to be spoiled to attract these flies. Blow flies will lay eggs on freshly cooked meat. In fact, blow flies may even infest the wounds of living animals. Sometimes when animals die in the chimney or crawlspace of a home, blow flies may breed in the carcass and the adult flies enter the house.
Flesh flies are grey and black with three black stripes on the back.
They are about inch long and resemble large house flies. As suggested by their name, they strongly prefer to breed in animal flesh. Unlike the other flies mentioned, flesh flies do not lay eggs, but small maggots. Flesh flies, like blow flies, will infest fresh meat, cooked or uncooked. Two other flies may be common pests in homes or businesses.