Last week Thursday we went and fetched our 3 cochin bantam hens from a guy nearby. Two of the hens are the same age and are actualy sisters. We wanted 3 hens so he said we could pick a third, which the boys did. The third one was held seperately from the 2 sisters with another flock. The 2 sisters are also a bit younger than the 3rd hen. So here is my dilemma/problem. I have read about dominant behaviour and hens having to establish hierarcy in the flock. The third one is clearly the dominant one. She chases the 2 sisters around and pecks at them. Luckily they run away. Tonight however the third one got on top of the one and kept on pecking her at the back of the head? The other one just lay there? Its not so bad that it draws blood or that a hen loses a feather, but Im not sure if this is " normal"? Are they still busy sorting out their hierarcy in the flock or should I be worried?