I have a friend with 15 hens and no rooster in a adequate coop and run. One hen that was or is alpha has a large bald spot on the front of her neck. I can't see any parasites on any of the birds. And this hen did rule the roost. My friend went to check on them last night and she was facing towards the wall with all but three doing the same. The other three were on the top roost and facing the door- opposite of the rest of the hens. Also the three hens were center of the roost. Has these three changed the pecking order or is there a health problem?