Answer: Mothballs do seem like a good solution, however we don't recommend them because they are so toxic. If you can find them now, it would be good to remove them. As long as you keep the mulch from touching the trunk of the trees, the voles and mice will be less likely to munch on them. Another good protective measure is to encircle the trunks with screen or tree guards, commercial products that you wrap around the trunks. Most nurseries carry them, and it's not too late to put them on.
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