Pigeons can fly back accurately to their homes from hundreds or even thousands of miles away  How do pigeons recognize the way home? This has been a mystery for a long time, attracting many people to study this issue  According to their hypothesis, some researchers put pigeons in tightly sheltered cages and transported them to an unfamiliar place  They can still find their direction home easily
If you put ground glass contact lenses on the eyes of the pigeons so that they cannot see things a few meters away, and then transport these nearsighted pigeons to more than 100 kilometers away and release them, they can also go home and accurately landed one to two meters near the pigeon loft-only at this distance do they need the help of eyesight
 The pigeon has a fairly sophisticated navigation system