The housefly is the most common fly species found in houses.
Adult flies normally live for two to four weeks but can hibernate during the winter. The adults feed on a variety of liquid or semi-liquid substances, as well as solid materials which have been softened by their saliva.
The female housefly usually mates only once. She lays batches of about 100 eggs on decaying organic matter such as food waste, carrion, or feces.
They can carry pathogens on their bodies and in their feces, contaminate food, and contribute to the transfer of food-borne illnesses, while, in numbers, they can be physically annoying.
For these reasons, they are considered pests.
Larval development takes from two weeks, under optimal conditions, to 30 days or more in cooler conditions.
The larvae avoid light; the interiors of heaps of animal manure provide nutrient-rich sites and ideal growing conditions, warm, moist, and dark.
The larvae depend on warmth and sufficient moisture to develop; generally, the warmer the temperature, the faster they grow.
The life cycle can be completed in seven to 10 days under optimal conditions but may take up to two months in adverse circumstances.
Houseflies can be controlled, at least to some extent, by physical, chemical, or biological means. Physical controls include screening with small mesh or the use of vertical strips of plastic or strings of beads in doorways to prevent the entry of houseflies into buildings.