We have almost finished building our coop and have decided to put down wire on the bottom of the run to hopefully keep predators from digging in. Once we do though, we'll obviously need to put something down on top of the wire. What is the best things to use...sand, pea gravel? We currently only have one hen. She is allowed to free range while we are home during the day. She will only be locked in the coop if we are not home and at night. The actual coop part has linoleum flooring for easy cleaning. Will I need to put something down on top of the linoleum as well? If so, what's best for that?