Ok so I have 18 chicks total. Seven are six weeks old as of yesterday, six of them will be four weeks old Friday and I just got five more today that are about two days old. Of the seven, six are silkies and one is a Rhode Island Red, who is a rooster. The 3 1/2 week olds are all black australorps. The new ones are all Rhode Island Red sexed hens. My problem is that my Rhode Island Red rooster seems is being very aggressive with the new chicks. For instance the new chicks went eat in front of him and he picked them up from their heads and dropped them. He did this to about three. I've now seen him run at them and at one point pull their little fluff out. To add onto the new chicks pain the silkies don't seem to be that nice however, when we got the black australorps some of they acted as if they were their own chicks and seemed to protect them. Will that happen with these new chicks? Also one of the ba chicks who I know is a rooster pecked the head of one of the new chicks. Will they kill the news chicks? Sorry for all of the writing but I figured you guys needed to know the background and how old they all are. Please help!