Yesterday, I came home to find a hen fatally wounded in the chicken pen. All of her head feathers were gone, eyes swollen shut and bleeding profusely. She was still alive. Got her to drink a bit of water and cleaned her up a little. She died before I could finish arranging a place for her to try to recover. When I went into the hen house, there was blood all over the lower walls as if another hen, or hens were chasing her around and attacking her. What happened here? I'm just sick about it and want to make sure it doesn't happen again. -Thanks.