When rotting flesh isn't around, they will get into things like garbage, excrement and other sources of filth. Their feeding habits make them a carrier of disease, as they can get inside the house and infect items through regurgitation or laying their eggs. Fly larvae are commonly called maggots, which hatch out and live on food sources. An interesting fact about the maggots is that they can be predators of other larvae, or even eat each other. All of these flies get more active as the weather warms up, and tend to rest when it's cold.
Flesh flies are similar in their feeding habits, and their nuisance to humans.
Flesh flies generally prefer food in a more advanced state of decay, and will eat leftovers from the bottle and blow flies. Maggots from the flesh flies have a couple of small differences from those of the bottle and blow fly. Flesh fly maggots are laid in their larval stage onto a food source, rather than being laid as eggs. Furthermore, flesh fly maggots will leave a food source and can be seen crawling around on their own, blow and bottle fly larva actually burrow into their food source. Despite their biological differences, these flies' similar habits make them comparable pests.