Hello all. At my home we have 2 bantam hens, a black cochin and a golden seabright. These lovely ladies live in a coop with an upstairs area closed in at 4' long, 2' wide, 2' tall. It can get a little on the chilly side in Kentucky and since there are only 2 tiny little hens it doesn't seem like they would produce much heat. What can we do to keep it comfortable for them in the winter. Currently we just have a 40 watt red bulb in there but it doesn't seem to heat up much. There is not yet insulation but we are thinking about adding some extra walls. What else would you nice people advise for 2 tiny chickens in a chilly winter? Thanks!