This species is found abundantly throughout the world, and in many countries, where sanitation is not adequate and human wastes are commonly deposited outdoors, the House Fly is responsible for the spread of numerous serious diseases. Included in this list are dysentery, typhoid, cholera, poliomyelitis, yaws, anthrax, tularemia, intestinal parasites and eye parasites. It is incriminated in the spread of food infections from bacteria such as Shigella and Salmonella.
The House Fly got its name from its common occurrence in homes, particularly during more rural times when horses and livestock were common around homes, and used as transportation. It breeds prolifically, with females laying from 350 to 900 eggs in their lifetime, with a record of 2,400 eggs from a single female fly. The interval from egg to adult fly can be completed in less than one week under warm, moist conditions, and there can be many generations each year. Adult flies live as long as 54 days and females mate multiple times. Breeding sites for the larvae will be any moist, decomposing organic material, such as piled lawn clippings, animal waste, filthy garbage containers, outhouse receptacles, and decomposing plant materials. The larvae commonly leave their food source to seek a drier location in which to pupate, migrating as much as 150 feet away, and thus appearing on floors or countertops they may fall or crawl onto.
The adult fly is only about 5 or 6 mm long, and is most easily distinguished by the pattern of wing veins, the 4 dark longitudinal stripes on the top of the thorax, and the yellow sides of the abdomen on the males. On the wing there is a distinct 90 degree upward bend of the middle vein as it nears the outer end. The larvae are a typical white, legless maggot, and the pattern of the lines of their spiracles, at the anal end, will be a distinctive characteristic for the species. The pupa is brown and egg-shaped, without any seams, and the emerging fly uses a pumping device called a ptilinum to force its way out of the pupa.