Flies are serious nuisances and transmit diseases through their foul feeding and breeding habits. They walk over food sources and rotting matter indiscriminately, carrying bacteria.
Apart from the biting flies, all species feed by vomiting saliva on to the food surface, treading it in 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. The eggs of parasitic worms may also be carried by flies.
Electric fly traps are very effective for a wide range of fly species, and there are various chemical treatments that can also be effective as part of a treatment course