I have a rooster who is about 7 months old. Yesterday I noticed he was chasing this one particular hen, a BO who was still in molt. (All my hens are just now coming out of molt and everyone is being more vocal and the rooster has been more "active".) He had chased her into a nestbox and he was picking at her at trying to pull her out of the nestbox. At this time her head was bleeding a little. By the time it was time to roost all was well. This morning I had an appt. to keep, but I checked on them before I left and all was well. When I returned home I found her laying in a corner barely breathing and badly picked and bleeding. Her neck was tore through the skin and her back was tore up and bleeding. The other hens all looked to be clean of no blood and was paying her no attention, and at this time the rooster wasn't either, but he was covered in blood. Now he has never been aggresive toward nobody and he has never attacked none of my other hens. This hen in particular was the last that was molting and she still wasn't laying and not fully feathered,..plus her head was pale. Could there have been something wrong with her and he took care of business (if that is even possible??) or do I have a aggresive rooster who needs to be culled??? Thanks.