When a pigeon walks, its head does not move back and forth regularly, but stretches forward all the time  As they walked, the pigeon leaned its neck forward, then kept its head still, waiting for its body and claws to follow
The change in the pigeon's walking speed stimulates the inner ear to control the balanced organs, resulting in neck stretching
 Some scholars have made hypotheses about the phenomenon that pigeons stretch their necks when walking: while waiting for the body to follow up, the temporary rest of the head helps the pigeons to get a stable field of vision and see the food around them