So I have a small ellivated coop. The button of the floor is a wood sliding door with a metal covering. One of my girls likes to move the litter and sleep on it. With winter coming I am worried her feet will freeze on the metal. I went to home depot and bought a cheap rubber memory foam mat and cut it to size to fit over the metal and under the sawdust. I am worried though it will cause bacteria to grow since it is a memory foam and very porus. Any thoughts?!