We have 2 ducks, 6 older hens, 10 hens and 1 rooster who are 10 months old. We have been noticing that some of our younger hens have missing feathers on their backs. We found one of our younger hens dead the other morning when we opened their house. She had some missing feathers and we saw a slice down her side. Yesterday my husband saw the rooster standing up straight stomping on a hen. She was flat on the ground being still. It did not look like he was trying to mate just stomping on her. Of course my husband went in and picked her up to make sure she was not injured and then seperated the rooster from the flock. The rooster so far has been docile around us and this is the first we have seen this behaviour with our hens. He is quite a bit larger than the younger hens. Is he just being aggressive? I don't understand the stomping on top of the hen behaviour. Can someone explain what is going on. I really appreciate it. Thanks.