Flies belong to the fourth largest animal order, Diptera, which comprises 95,000 species of two-winged insects. The Diptera evolved from four-winged insects, and their vestigial rear wings are stalks that act as gyroscope balance organs, enabling the forewings to move the fly forward without causing nose dives, and keeps it on a steady course. Dipterans occur worldwide, including Antarctica, but are most plentiful in moist,warmclimates. The main dipteran suborders are Nematocera, Brachycera, and Cyclorrapha. Nematocera are mosquitoes, slender, with long antennae. The other orders have stout bodies and short antennae; among them are houseflies and tsetse flies.
Physical Characteristics of Flies
Afly body has three parts: a head, thorax or middle part that holds six legs, and an abdomen or rear end. Two compound eyes containing up to four thousand facets cover most of the head. The eyes see light changes and sudden movement from many different directions at once. This is why flies are hard to catch Atop a fly's head, paired antennae provide the senses of touch and smell. Dipterans have a mouth part called a proboscis. It is funnel-shaped, with its wide part at the bottom. The proboscis is like a straw, sucking up fluid via a pump in the head. The proboscis of a housefly is soft, so it cannot bite. Bee flies have a long proboscis that enters flowers for nectar. Biting flies, such as horseflies, have hard, sharp proboscises that pierce the skin of their victim. Each foot on a fly is tipped by claws that grip rough surfaces. Under the claws are pads called pulvilli. On smooth surfaces, they flatten and grip tightly, allowing a fly to walk upsidedownon ceilings without falling. Flies breathe through openings called spiracles, located on each side of thorax and abdomen.
Thanks for description - Animal life club