Flies are maggots. Fly is a completely abnormal insect. Its life experiences three stages: egg, larva (maggot) and pupa. Maggots are the larval form of flies. Flies often lay their eggs in toilet feces. After the eggs hatch into maggots, they feed on feces. Flies like to lay their eggs in rotten meat and walk by wriggling. Flies have the physiological characteristics that one mating can lay eggs for life. A female fly can lay eggs 5-6 times in a lifetime, with about 100-150 eggs each time, up to 300 at most.
Flies move frequently in the daytime and have obvious phototaxis. At night, it perches still. Activity and habitat depend on fly species, season, temperature and region.
The common housefly, big headed golden fly, mercerizing green fly, Calliphora and hemp fly belong to omnivorous flies, which widely eat human food, livestock and poultry secretions and excreta, kitchen waste and organic matter in garbage. （CangYingShiQuBianDeMa）