I have a small backyard flock of 8 hens consisting of three 3-mo-old Silkies, one 3-mo-old Frizzle, one 3-month-old Ameraucana, two 4-mo-old Buff Cochin bantams, and my super dominant 2-yr-old white Cochin bantam. The problem I am having is that my white Cochin co-habitates fine with the rest of the flock during the day (save a peck here or there), but right around dusk when the others are ready to go into the henhouse to roost, she stands at the door and refuses to let them enter. I have to remove her (to a dog kennel) just so the other 7 can roost! This has been going on for weeks, and I don't want to have to get rid of my white Cochin. Any suggestions as to why she may be doing this?