I went out to feed and put the animals up for the evening. One of my Buff Rock hens was in a nesting box. Two other hens were pecking at her rear under her tail. I chased them off and realized the hen was bleeding. I lifted her up enough so that I could see where the blood was coming from. It looked like she had tried to "lay" her internal organs rather than an egg. I've had chicken for 30 years and have never seen anything like this. Does anyone in the backyard know what happened?