I got up this morning to find 1 of my hens laying on the floor of the roosting room. She can't walk, I looked at her and she's missing feathers on the right side of her head, a little on her back, and her neck moves from side to side. I'm trying to help her out but its not looking hopeful. I decided to investigate the roosting room, I found a hole, and some rodent droppings. None of my other chickens are hurt. I have been dealing with a weasel but I believe the weasel is dead by now and this doesn't seem to be the same method of kill. If anyone has any ideas on what this could be I would really appreciate it. One more thing, would hens kill each other and how would you tell if that was the case.