My first batch of five chicks arrived a week ago and they are growing like crazy. One of the two buff orpington is noticably larger than the other chicks and now it is squaring off with all of the rest of them and jumping on their backs. It has been terrorizing all of the other chicks for the past 24 hours. To my knowledge, this is normal behavior but I do wonder if the jumping on backs is a precursor to mating behavior and that this "big one" might be a cockrell? I hope that this is not the case as roos are not permitted in my city. Any thoughts would be greatly appreciated.