The life cycle of a house fly consists of the egg, larva, pupa, and adult stages. The total duration of these stages is approximately 15 to 30 days, after which the house fly will die.
The first stage of a house fly's life cycle is the egg stage. Female house flies can lay up to 150 eggs at one time and typically lay five to six batches of eggs.
Within one day, house fly eggs hatch and turn into larvae known as maggots. Maggots are white insects that have no legs and stay near the location the eggs were laid to feed and molt.
After three to five days, the maggots seek a dark location to pupate. During this stage, the pupa forms a hard cocoon around itself that provides protection until the pupa develops legs and wings.
Within three to six days, the pupate emerge from their cocoons as adult house flies. Two to three days later, adult female house flies are capable of reproduction and can begin laying eggs.