I have 4 3-week-old chicks: 2 Rhode Island Reds and 2 Plymouth Rocks. The PRs seem bigger (older) than the RIRs. Recently, i have installed a roosting pole is their home and the PRs love to roost on it. I am trying to get the RIRs to roost on it too, but when i sit the on it, the PRs snap at th RIRs' tail feathers. Is this a dominance issue or a pecking issue? Please Help.