While house flies live only about two and a half weeks during the summer, they can survive up to three months at lower temperatures. Flies normally stay within a half to two miles of their point of origin, but may travel up to 20 miles to find food and egg-laying sites. A female fly deposits 100 to 150 eggs in decaying matter such as grass clippings, garbage or human and animal waste, Oi says. Depending on how warm it is, the eggs hatch into maggots between eight hours and two days. Mature maggots burrow in cooler, drier surrounding areas, where they form pupal cases and mature into adult houseflies.
Adults mate within two days of emerging, and the cycle begins again.
Oi says there are four basic ways to control houseflies. Sanitation is most important, because flies can't breed in large numbers if their food sources are limited. Don't let garbage, grass clippings, weed piles or other decaying organic matter pile up. Keep trash cans clean and tightly covered. Don't wash the cans where the rinse water drains into the soil, because flies may breed in the soil.