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.