The preferred diet of the mole is a carnivorous one. The mole will eat worms, grubs and adult insects. Neither the eastern mole nor the star-nosed mole is a rodent, so any gnawing damage you find on plants is unlikely to have been perpetrated by a mole. But rodents do exploit mole tunnels to wage subterranean war on plants, thereby making the mole an accessory to the crime!
The vole, by contrast, is a rodent. A vole will gnaw at the base of a tree or shrub, especially in winter; thus the metal guards sold to prevent such vole damage. A vole may also damage flower bulbs and potatoes in the garden. But mainly, the vole will eat the stems and blades of lawn grass. And the runways they leave behind in the process make for an unsightly lawn. Voles can also inadvertently damage plants by burrowing into the root systems of trees and shrubs, causing young specimens to experience dieback or to begin to lean.
Why is it important to know the difference between a mole and a vole? Well, here's one reason:
If you realize that the mole is mainly a carnivore, whereas the vole is a primarily a vegetarian, you'll know that they won't necessarily be attracted to the same baits (should you decide to try to catch one of these garden pests). A vole may be attracted to peanut butter as a bait; a mole most likely will not.
For more mole and vole information, please consult the following articles: