Life cycle of the black blow fly
Adult female blow flies arrive within minutes to lay eggs on a cadaver. Each deposits about 250 eggs in the natural openings of the body and open wounds. The eggs hatch into first-stage maggots within 24 hours. These feed and then molt into second-stage maggots, which feed for several hours, and then molt into third-stage maggots. Masses of third-stage maggots may produce heat, which can raise the temperature around them more than 10° C. After more feeding, the third-stage maggots move away from the body and metamorphize into adult flies.