I have always had hens as I just had no desire to have a Roo. But I decided I really wanted some Black Copper Marans and I got a deal if I took a trio,so I did. The hens are just fine in my crew but some of the hens have decided to start pulling out the tail feathers of the Roo. He is only 4-5 months old. My hen group vary in ages from 5 months up to 1yr. and I have added chickens to the group to get up to the number I have now,I didn't buy them all at once and there has never been and issue. I have seperated the Roo for right now but I really want him in with the crew as I may want to try and hatch some eggs later on. Any suggestions on what is going on and how to make it stop would be great.