Yesterday I noticed a mouse dug under the edge of the coop run to get to the feed inside. I have large stones around the outside edge, but they are irregular and it found a small spot it could get in. Rats wouldn't be able to get in, but mice can. I have 3 four month old gold laced wyandotte bantams and they seemed concerned about the mouse and were sticking to the opposite end of the run. My question is if mice are actually a problem? Should I just ignore it, or should I do something about it? I am an organic gardener and won't use poison. Any suggestions?