My dwarf mondo grass is established and beginning to produce side shoots, but something is eating it down to the ground. Unless I find a way to discourage the perpetrator, I can't see how it can survive. There are no deer here, but I have seen a rabbit and several chipmunks and squirrels. Is there something I can spread on the ground around the plants (mothballs?) or spray on them to deter these munching critters? Could it be an insect? Earwigs perhaps?