A typical house fly lives between 15 and 30 days. Having warm temperatures, food available and an environment with a lack of hazards will help flies live longer.
If food is available, flies can multiply quickly. Their primary food sources are food waste, organic garbage and feces. A single fly can lay around 9,000 eggs during its life. Fly eggs hatch within 24 hours to produce maggots, the first stage in their development. If maggots survive the first 14 to 36 hours, they transform into pupae and thereafter into fully grown flies. Houseflies are considered dangerous pests because they frequently carry diseases that affect many other species, including humans. Over 100 diseases have been discovered in flies, with tuberculosis and cholera being two of the more serious conditions they may carry.