One of my chickens, who is about 8 months old or more, has started pecking, plucking and drawing blood from my Polish rooster's top head feathers. It's been a while that this has been going on but just recently she started drawing blood. The rooster in no way defends himself, isn't it supposed to be the other way around? I got them both at the same time, when they were about 4-5 months old and she has always been a little mean.. I am first time backyard chicken owner so I don't know why this is happening. Anyways, I ignored this behavior until something terrible happened. About 3 weeks ago I got a 4 month old chicken, and I kept her alongside the others' coop so they could see each other. Nothing happened for about 2 weeks, and I finally placed her into the coop. The rooster slightly bullied her but then they became pals, sharing the same roosting pole and literally cuddling together. The other chicken was not happy. When she'd get the chance, she'd pluck a feather from her and the rooster would actually defend the little one! I read somewhere on here that it was normal. 3 days later, after coming home from school the little chicken's tail feathers were almost gone, her back was bald and bleeding A LOT and the scary part, both the other chicken AND rooster seemed to be eating her! I immediately seperated the little one, and it seems like she will heal. I apologize for such a long post, I just thought it was important to know how this started and so on. A few details, they have a fairly large chicken run and they always have some grass or scratch to mess around with, and dirt. I'm sure that the evil chicken wasn't just 'bored'. So what can I do about this evil chicken?