We had something trying to dig under the coop. Couldn't rule out Chihuahua. I put a wire skirt around the coop. Put the rubber mulch back in place. Mulch was moved in the morning before Chihuahua was even out, so he was ruled out. Didn't have wire skirt on one side (was big enough for a rat), so Sunday I took down 4 foot of fencing, installed the wire skirt, put fencing back up. Got out the Game Cam and set it up. Caught the culprit on the game cam. It was a rat. Put out the bait boxes.