How Flies Get Into House
While house flies usually breed outdoors, they are also able to get into houses. Typically, they enter a house through a crack or hole in a wall. Their favorite spots are the kitchen garbage bin and dirty drains. House flies lay their eggs in decaying organic matter.
Flies like warm temperatures and will seek out areas of warmth and food. In winter, they can even go into hibernation. During the winter, female flies try to find a place to lay eggs. Once inside the house, they will remain for two to four weeks before leaving.
The first sign of a fly infestation is maggots, or the larvae of a fly. When you find maggots in your home, this is a good indication that flies are breeding. Different types of flies have different breeding sites, so it is helpful to check your garbage cans, drains, and compost. Also, you should keep an eye out for large flies. You can spot them by their size and the buzzing sound they make.
The flies may also get into your house through a number of different entry points. In the yard, they can enter through pet waste, trash cans, compost heaps, and manure.