I had a cockerel starting to get mean and pick on his brooder mates, I was woke several times in the night with him chasing and jumping on the others I put him in with the next set older and he calmed down had to put the rest of his age in with the older set to put in the 20 chicks I bought yesterday and he started to pick on the younger ones again well older roo told him NOPE!!, he protects all his lady's including the new younger ones. It stinks because The little guy is a splash roo that is my son's and the gentlroo is a mix I was planning on selling. OH well. The younger is 1 1/2 months old and the older is 2 1/2 months, and the younger has been handled a lot more then the older ones, I am working on showing dominence so hopefully he will straighten out.