Primarily active in the summer and found in more places on the planet than virtually any other insect, the house fly accounts for more than 90 percent of all flies in human habitations. Despite relatively short adult life-spans of two weeks to a month, house flies produce huge broods that can quickly lead to infestation. With a well-earned reputation for spreading disease and an increasing immunity to pesticides, house flies may pose serious health threats to humans and pets.
Adult house flies are usually gray or black and can be distinguished by the four black lines running across their thorax. Adults measure 4 – 8 mm in length and have hair-like projections covering most of their bodies. Typically, females are larger than males but both have red, compound eyes and sponging-sucking mouths used to eat liquid and saliva-dissolved food stuffs. House flies are active during the day and will hide or rest in high places to avoid detection and threats.
House flies eggs are typically laid amongst larval food sources and hatch within a day. Known as maggots, the fly larvae are pale white, 3 – 9 mm long and legless. After 14 – 36 hours, maggots will move to a cool, dry spot and transform into reddish-brown pupae from which adults wills then emerge. Females can mate as soon as 36 hours after emerging from the pupae.