I have a small flock of buff orpingtons (two 5 year olds, ten 12 week olds) with a recently added cute little amber link. They get along great. We were given five 2 year old red sex links, which we kept quarantined, then were kept in sight of the buffs for a few days. Unfortunately, they seem to want to kill the pullets and have even attacked and drawn blood from my old ladies. I cannot determine the ringleader, it seems to be a group effort with these girls. My husband has gone so far as to build them their own little coop, but if they are let out to free range with the others, (we have over 3 acres) they go back into attack mode. They are quite friendly to humans and lay really well, but I have to think of what to do with them. I hate to think of not being able to let them out.