Good morning! I am looking for some ideas for a heat source in my coops. I live in northern Wisconsin and the winter nights(and some days!!) can get quite cold. Nearing zero and below. I currently have a 4 by 8 coop, with foam insulation and covered so they dont peck it. Someone has told me to simply use a 100 watt bulb. First question, wouldnt that keep them up at nite? Could I use a red light? Any advice? Thanks!