I have a flock of seven 8-month old pullets and a flock of eight 12-week olds (4 definite pullets, 1 definite cockerel - the other 3, I'm not sure). For the past three weeks they have been living in separate coops - but the runs of the coops are only separated by hardware cloth. So they have seen and heard each other constantly for several weeks - and were frequently beak to beak through the hardware cloth. I've also let them out to free range together several times. When they're out in the yard together, there have been a few scattered power struggles - but nothing that wasn't settled quickly and with no injuries. Most of the time each flock sticks together in different areas of the yard. The only time we had a problem is when one of the younger ones wandered into the other coop when all of them were out in the yard. Then he couldn't figure how to get out - and the older birds started pecking at him when they returned. I finally had to rescue him because he couldn't find one of the four wide open doors. Today we got our new (large and improved) chicken house, and my plan is to put the two flocks together on Monday. I thought that since the chicken house will be new to both flocks, there won't be problems because one flock feels that the other flocks is invading their space. Any advice for how to handle this integration of flocks?