About l00-l50 eggs are deposited by each female on appropriate food. Maggots lack definite heads, eyes, antennae or legs. Their bodies are pointed at their front end and gradually widen at the rear. They feed on the material in which they find themselves. There are three larval molts.
Mature larvae stop feeding and burrow for protection in drier surrounding areas, where they pupate.
The pupa is a chestnut brown, oval object within which the larva changes into an adult house fly. Adults mate within one to two days after emerging from their pupal cases. The life cycle, from egg to adult, may take as little as one week, but normally requires three weeks for completion. Some overwinter outdoors in protected locations, or in crevices in buildings. These are listed in order of lasting effectiveness.