We remodled an old ice shed for our chicken coop, however I'm finding the shavings are getting damp and I AM getting frost sometimes. I want to add some vents, but I'm not sure what to do as the walls are about 8 inches thick. Is there any kind of pipe vent I could use that would let air circulate without letting things like mice, or other animals in? Note: I already have a resident deer mouse, she lives in the big concrete bunker and can't get into the main building. Actually, to be honest I have no idea how she even got in the bunker LOL.