housefly

The housefly (also house fly, house-fly or common housefly), Musca domestica, is a fly of the Cyclorrhapha suborder. It is the most common of all domestic flies, accounting for about 90% of all flies in human habitations, and indeed one of the most widely distributed insects, found all over the world; it is considered a pest that can carry serious diseases.

http://en.wikipedia.org/wiki/House_fly