I have 2 Easter egger cockerels, aged almost 16 weeks. They have recently become very mean to my pullets. Chasing them and pecking. Today they attacked several times over the course of an hour ending with the near scalping of my buff Orpington. I was in the process of cleaning her up and sorting her out when I saw them penning my RIR against a fence and attacking her. I say "they" because once one starts the other joins. I've never had roosters before and am wondering if I need to deal with this now or if they'll grow out of it.