The typical life span of an adult housefly is 15 to 30 days. Females begin laying eggs after just a couple of days, and they continue to lay eggs for most of their adult lives.
Prior to living their adult lives, flies go through a few stages of development. Eggs hatch into larvae, often referred to as maggots, less than one day after being laid. The larvae remain in this stage for four to 10 days before entering the pupa stage, which lasts another three to six days. A warm home or lab-based environment helps contribute to extending the fly's total lifespan.