Why is it easy to attract the sky?

When the raising pigeons fly in groups, it is easy to turn the pigeons band, which causes the sky.Usually the most falling pigeons in the spring and autumn, because the spring and autumn are the season, people fly pigeons, so it is also the most likely to produce tattoo pigeons, and it is easy to see in public sheds, squares and other places.As we all know, the pigeons have the characteristics of returning to the nest, but this characteristic is not necessarily reflected. If the pigeon who places the pigeons meets the pigeons on the road, it is easy to be taken away by the pigeons.