Flies are the most common insects. They are known for their dirtiness and many people think that they are responsible for spreading diseases but there are only few kinds which spread diseases.Flies have great variety in ways of living. Some of these seem to us to be unattractive, but even flies that live on decaying plants and animals are important. These are recyclers. Which means they help change dead things into chemicals which plants need to grow, so that the plants may use them over and over again, others are pollinators, as they carry pollen from flower to flower. Many kinds of animals and birds feed on flies.

Flight

All flies use only one pair of wings to fly with. Their back wings, which are very small, are used only to balance them as they fly. The movement of the wings is very fast in many flies. Houseflies beat their wings about 200 times each second, mosquitoes about 600 times and some of the smallest midges at a rate of over 1,000 times a second.

Shapes

Flies vary a lot in shape. One big ground, that includes all the mosquitoes and midges have slender, soft bodies. The daddy-long legs which is easy to see because it is so large, also belongs to this group. It is harmless, but many of the adults in this group have biting and sucking mouthparts and the females feed on the blood of mammals or birds. A second group, which includes the horseflies and clegs have short, hard bodies. The females also feed on blood, although the male feed only on plant juices. The third and largest group of the flies is the one which includes the houseflies and hoverflies. All of these have short, well armored bodies, and most feed on liquids of various kinds. A very small number of these flies feed on blood.