The average housefly likes to rest indoors on wires or ceilings at night; when outside, a housefly rests on edges of buildings, plants and fences, according to the Texas Agricultural Extension Service. Whether indoors or out, flies prefer to rest in corners, edges or along thin objects.
Flies also try to rest near daytime food sources, including cabinets and counters. Houseflies are typically found 5 to 15 feet off the ground.
When spraying a home for these common household pests, it is a good idea to keep in mind the areas of a house that houseflies prefer. Targeting those areas ensures the most effective results.