So I built a coop that has a window and is insulated for my chickens. This one is 7x7x8 ft and the old one that was 3x3x3. This batch of chickens is 8 and a half months and they spent the first 6 in the small one and free ranging then I moved them to the big one and they still free range. Up to about a week and a half ago I finally started to get 5 to 7 eggs a day from the nine of them. Then it started to get cold, it snowed and we got this inversion where I live so it stays cold in the valley, and all the snow is melting very slowly. Anyway where I am going with this is they don't come out of the coop at all. After it snowed their egg laying decreased to a few a day and then it stopped. Now they just sit in the coop all day. I don't think I insulated it enough though because the water is still freezing pretty good every night. Is there anything I can do to help them to lay again like a light or heat the coop some way or am I just going to have to wait for the day's to get longer again, and what is the problem?