The life cycle of a house fly begins in the egg stage. A female house fly is capable of laying up to 150 eggs in a batch.
Over a period of a few days, she will produce five or six batches of eggs. Female house flies favor damp, dark surfaces such as compost, manure and other decomposing organic material for egg laying. House fly eggs resemble individual grains of rice.
Within a day, house fly eggs hatch into larvae, also known as maggots. Maggots are legless, white insects that feed from the egg-laying site for three to five days. During this time, maggots molt several times. They then choose a dark place to pupate.
Fly pupae are similar in function to butterfly cocoons: their hard, brown shells protect the inactive, developing flies. Over the course of three to six days, the pupae develop legs and wings, ultimately emerging as full-grown house flies. Within two to three days, female house flies are capable of reproduction.