I have a 4 x 4 x6 coop attached to a completely chicken wired 10 x 12 run. The coop is not insulated and I don't know whether there is enough space to run a light to the coop to get my 6 month old Barred Rocks, Buff Orpingtons, and 2 ameraucanas to begin to lay. I live in western Maine and we are not getting the daylight needed. I have roosts in both the coop and run and the coop is currently always open for them to go into. I was going to use 3 mil Plastic sheeting to keep snow/wind out this winter. Can I use a light in the Run and not the coop as "daylight"? Also is 3 mil thick enough to keep some elements out or do I need to use a thicker gauge, i.e. 5 mil or 6 mil? Any help would be greatly appreciated.