Energy is transferred to the wings from powerful muscles within the insect's thorax, but like sails on boats, wings largely depend on the arrangement of their supporting framework. During flight, the wings become distorted by the shifting forces acting upon them, but in a useful and efficient way. Accompanied by complex wing movements, which are often in a figure-eight pattern, wing distortion provides insects with tremendous mid-air maneuverability. In hopes of developing something of great practical use, engineers have been trying to replicate the intricate wing structure and motions of insects for many years. If their attempts prove successful, the advances in flight technology could be phenomenal.