Flap wings is a term used to describe the motion of a bird's wings when they are in flight. Flapping wings is a form of powered flight, where the wings move up and down to generate lift and thrust. The term 'FLUTTER' is often used to describe the same motion, which is characterized by rapid, alternating movements of the wings. Flapping wings is an essential part of bird flight, and is used to gain altitude, maneuver, and even hover.