We turned our old shed into a coop and built an attached run. The run is 12ftx8ftx5ft. We used leftover 2in x 4in fencing from another fencing project . But now that it is up it looks like just about anything other than large predators can get in there. The fencing is on all sides, the top and covering the windows. Any recommendations on what I can do to keep things like snakes and weasels out?