Blowflies belong to the insect family Calliphoridae and resemble the size and appearance of houseflies. Some species are metallic blue or green and are consequently referred to as bluebottle or greenbottle flies.

In flight, blowflies make a characteristic loud buzzing sound and they will feed on most anything. The larvae of most species, however, are scavengers that subsist on decaying flesh or other organic material. Occasionally, blowfly larvae will inhabit lesions of living animals, which helps to keep wounds clean, but also frequently damages healthy tissue. A variety of sterile blowfly larvae, referred to as surgical maggots, were utilized in World War I to help treat the wounds of injured soldiers and prevent the spread of bacteria.

Adult female blowflies are extremely fertile and may lay 200 to 400 eggs in a single location. A large blowfly larvae infestation in a living host is known as myiasis and may lead to the death of the animal. Outbreaks of myiasis, particularly on cattle ranches, can lead to large economic losses. Sterilization of male blowflies, however, has been successfully utilized to help stem the problem.