Ok so I have 4 Cochin chickens and they are hens about 3-4 months old. They do this chest bumping thing and then they give each other this stink eye and bob their heads up and down and then start doing more chest bumping. Sometimes this will go on for 1-2 minutes. Its really funny because they are not hurting each other and it seems to be a game to them. What is all this about though, is this normal?