A family of two-winged polluters that is, too often, tolerated within our homes.
Apart from the biting flies, all species feed by vomiting saliva on to the food surface, and sucking up the resulting liquid. In the course of doing so, the fly contaminates the food with bacteria from its gut and its feet. Thus, it may transmit food poisoning, dysentery, typhoid or cholera in countries where these occur.
The eggs of parasitic worms may also be carried by flies.