House fly is a gray in color, 6 to 9 mm. in length, having spongy type of mouth parts. They laid eggs in moist decaying organic matter, particularly in manure and garbage. Each female lays batches of 100 to 150 eggs, over a 3 to 4 days period. If temperature is high eggs may hatch in 7.5 hours, other wise it take 1 to 2 days for them to hatch. The Fly life passes through following stages- Egg, larva, Pupa and adult. Adult flies lives up to 2 weeks to 2.5 months.