DrPhotoMoto;
The hump on the back of the robber fly (Family Asilidae) is mostly for protection. It is a shell, called cuticle that protects the muscle mass conected to the wings and other internal organs. There is a thick, leathery looking membrane that allows the wings to go through the cuticle and attach to the wing muscles. Some robber flies are so large, like the giant robber fly you can hear a whirling sound when it flies near you. Robber flies are predatory and very important to the ecosystem by eating other insects, some that are dangerous to humans.