I thought I'd share what we did to integrate 18 month old hens with new pullets (16-20 weeks old). We put pinless peepers on the 4 "old" hens and took them out to the garden beds to look for bugs and worms. Then we let the new pullets into the coop and run to explore, find the food and water and get used to their new surroundings without the ladies around. After a few hours we let the old ones back in and then we sat back and observed. We made sure there were lots of different places with BOSS semi covered by dirt for scratching, and had two food and water stations so there was plenty for all. There was a little chasing off and a few head pecks from the older hens, but relatively little drama. Over the next few days, they had established the new pecking order and things seem to have gone well. They have been together for almost 4 weeks now. The peepers are still on (I'm kind of nervous to take them off). I was really nervous to integrate the new chickens after reading all the nasty things that others have had to deal with, but I'm a believer in the peepers!