Why do pigeons bob their heads?. Researchers have used various studies to find the mechanics and reasons. In a landmark treadmill experiment, the pigeon was put on the treadmill and its slow-motion footage studied. It was found that there were two main parts to a pigeon’s head movement, which the scientists called a “thrust” and a “hold” phase. In the ’thrust’ phase, the head is pushed forward, relative to the body followed by a ‘hold’ phase, during which the head is kept still in space. Head-thrusting helps pigeons to stabilise their vision of the moving world around them.