I introduced 2 hens 8 months to my old flock of 6 pullets. The first hour was not so good, I removed the trouble maker for an hour and when it returned to the flock it calmed down. That night was great, then the next day another started pecking and fighting, I did the same to that one and I got the same results. It has been about 24 hours since the last incident and they seem to all get along great, no more pecking, cowering, and there even mixing into the areas there were not before. I think the key here was to remove the chickens that were picking on the new ones and not to remove the new ones getting picked on. I think this was a good time to introduce the new hens since the younger ones are not perching yet and they are not using the nesting boxes ect. Not sure if that made a difference? Also when I introduced them I placed them in the run first not the coop and it was a few hours before their bedtime. Maybe I did nothing at all and the natural order has taken place...either way I am soooo happy they are all getting along.