I added 4 hens to my existing 4 hen flock a week ago. I understand about pecking order and hierarchy, but the old hens won't let the new hens in the chicken house at all! It is getting into single digits here weather wise, and I don't know whether to let nature take its course or to put them all in the house (which is where the heat lamp and water is) and lock them up! Please, I need advice from chicken pros!! Thank you!