Update. I went out yesterday and the big rooster looks like he's been pecked on his back near his rear. It is a large ugly bloody spot. Does anyone have any clue as to what is going on? Hello, I removed a hen from the chicken coop because she had a bald spot on her rear side. She wasn't moving much. I put her in a dog crate and she is now very active and alert. That was about a week ago. Now I go in the coop and find a dead hen. Looks like the same sore. I don't know if they are being pecked or maybe a fox got a bite of her if she was sitting too close to the fence.