My oldest set of chickens are 10 weeks old. They all came from the same place, and it only took a short while to work out their pecking order, with no injuries. They were pretty civil about it. In the past week they have started crowing, though (I ended up with 5 out of 6 cockerels *sigh*) and for some reason one of them has become VERY aggressive with the other chickens. He tried to mount my dominant cockerel last night and has been pecking and trying to fight with the rest all day today. He isn't aggressive with us...yet. Is there anything that I can do? He isn't the one we plan to keep as our roo, so he is eventually going to end up being culled anyway, but I refuse to keep an aggressive chicken, roo or hen. At what point would you call it quits and remove him? How much more aggressive should I let him get before I step in? He's also been very aggressive with my 4 week old chicks, who have been free ranging with my supervision. He's not just being dominant, he's being mean. My dominant chicken pecks at them, etc, and is totally different. (I am acting as mama hen and stepping in and trying to prevent as much interaction as I can at this point b/c my 4 wk olds are so much smaller than the 10wk olds.) Any advice would be greatly appreciated. Thanks!!