Stool pigeon

One method of killing passenger pigeons was to blind a single bird by sewing its eyes shut using a needle and thread. This bird's feet would be attached to a circular stool at the end of a stick that could be raised five or six feet in the air, then dropped back to the ground. As the bird attempted to land, it would flutter its wings, thus attracting the attention of other birds flying overhead. When the flock would land near this decoy bird, nets would trap the birds and the hunters would crush their heads between their thumb and forefinger. eg. letter to Time Magazine, Dec 29 1930

There is a debate about whether this method of capturing the passenger pigeon is really the origin of the term 'stool pigeon' - used today to refer to an informer, but originally used to refer to a person used as a decoy to entice criminals into a trap. However despite the debate over the etymology of the term it is clear that this was an actual method used to capture large flocks of passenger pigeons.