I am building a 4x6 moveable coop/run combo but don't know how to prevent predators from getting into the run from under walls. If this were a fixed-location coop, I know that I'd dig it into the ground to insure that animal couldn't burrow under it; with this being designed to move every few days in a backyard with VERY little flat/level ground, I'm not sure how to go about protecting the hens. Should I put chicken wire along the bottom of the run/coop in addition to all the sides? Will that hurt the chickens or will it not bother them? Should I pile up sandbags along the edges and just move them with the coop? Any suggestions would be greatly appreciated-- THANK YOU!!!