We are off to a great start with our babies, they are growing like weeds. We have 12 little ones. 3 bantam cochins, 3 silkies (All 6 weeks and straight run), 1 rhode island red, and 5 americaunas ( all 4 weeks and pullets). The 4 weekers have been in a pen with 1 of the very sweet and gentle cochin and 1 silkie (like a little mommy). I am completely in love with them, so friendly. The other 2 cochins and 2 silkies have been in another pen together and do just fine. I am beginning to notice that 1 cochin in this group has recently become aggressive. He or she will let me pick it up and will eat from my hand one minute and run at me with fluffed feathers and peck me the next. Lately....just the pecking is the favorite past time. Yesterday, I picked up the other cochins and it ran at me all fluffed up when I picked the other one up and when I put it down. I did have to combine the two groups together yesterday and all was well...except that one cochin. It was bullying everyone and then he enlisted another cochins help to do the bullying. All the chicks got so upset and stressed out that I had to remove the two cochins. Is there any indication that this is a roo or just a prickly hen? I don't mind a roo if he can behave himself, but not if he is going to be like that. Is there any way I can kill it with kindness and calm it down? I have a 3 1/2 year old daughter and I don't want to this bird to scare her into not wanting to be around the rest of the chicks or run up on her and peck her like it does me. Any suggestions would be appreciated.