I have 5 hens and 1 rooster. We had our first frost the last 2 nights. My coop is rather large, at least 90 sqft. They have plenty of room on the top roost pole for all 6 of them, which is where they all go... To the top. There is a small window 2"x4' they can look out of when they are on the top roost pole. On the opposite side of the coop there is a 1'x1' window about 3' above the ground. The coop isn't sealed tight, so it is already pretty drafty. I am doing the deep litter method, but had to restart it about 2 months ago so I could train my hens to lay in their nesting boxes. Do yall have any ideas to help keep my birds warmer in the soon to come colder months. I do not want to run electric to the coop, or use a heat lamp. I live in Central VA.