Most species are not synanthropic. Adults can be predatory, hematophagous, saprophagous, or feed on a number of types of plant and animal exudates. They can be attracted to various substances including sugar, sweat, tears and blood. Larvae occur in various habitats including decaying vegetation, dry and wet soil, nests of insects and birds, fresh water, and carrion.
The housefly, Musca domestica, is the best known and most important species.