Kingdom: Animalia
Phylum: Arthropoda
Order: Diptera
Suborder: Brachycera
Infraorder: Muscomorpha
Subsection: Calyptratae
Superfamily: Muscoidea
Family: Muscidae

Muscidae, some of which are commonly known as house flies or stable flies due to their synanthropy, are worldwide in distribution and contain almost 4,000 described species in over 100 genera. 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.(Text from Wikipedia)

A Muscidae fly with a blue abdomen.

House Fly family Family Muscidae .JPG
House Fly family Family Muscidae -001.JPG 

Thanks to Wikipedia for text and information: https://creativecommons.org/licenses/by-sa/3.0