I have only had chickens for a few years now, and never used heat in the winter, but want to get some feedback. I have two hens that are in a bad molt right now, They are nearly naked and temps are dropping below zero night and the wind is making the days frigid as well. The water is always kept outside in the pen, but they two hens won't leave the door of the coop. I have moved the water as close to the door as I can but I haven't seen them go out for days now. I have plastic tarps up to stop the wind, but do I also need to heat the pen so they will come out???