I had more than one roo, but they had plenty of room in the yard and they were from two different hatches so the older of the two was the dominant and had "his" hens and the littler had hens that hatched at the same time as him. I never had any fighting between them it just got really noisy in my yard and I wanted some peace and quiet and nicer tail feather on my hens and over time he got more aggressive with my girls and they would run. Running them ragged I think is they the key phrase for that behavior. My second roo became evil after we got rid of the dominant roo, he doesn't even mount them he just rips out their feathers so we have him separated from the girls now. He'll be dinner soon enough it's too bad too he's a mix buff cochin ameraucana truly an exquisite looking bird.