Moles and Voles – What’s the Difference?

As most people have begun mowing their lawns, they may have noticed the familiar mole runs or a curious above-ground network of runways. This is perhaps the most visual difference between the effects of moles and voles. I will discuss differences in the animals, other types of damage, and management options utilizing information from Purdue Extension publications.

First, the animals themselves.

There are two species of moles in Indiana. The Eastern mole (Scalopus aquaticus) is the most numerous and widespread and is responsible for most of the complaints concerning mole damage to lawns and gardens.

Moles belong to the group of mammals known as insectivores and thus are related to the shrew. They feed primarily on earthworms, beetle grubs, ants, and other animals which live in the soil. A smaller part of their diet consists of various seeds and vegetable matter. Eastern moles have pointed snouts, greatly enlarged, rounded front feet with stout claws, and a short, nearly naked tail. They are six to eight inches long with short, velvety fur that is usually gray to silvery-gray. The eyes and ears of moles are very small and are concealed in the fur.

There are three species of voles in Indiana. The Meadow vole, Microtis pennsylvanicus, is the most common. People often refer to voles as meadow mice or field mice. However, they are not the same animal as a mouse that you may find scurrying across the floor in your house.

In general, voles are compact rodents with stocky bodies, short legs, and short tails. Their eyes are small and their ears are partially hidden. They usually are brown or gray, though many color variations exist. The adult vole ranges from 3.5 to 5 inches in body length (5-7 inches including the tail). The front feet of voles are noticeably mouse-like rather than the powerful and large front feet of moles that are used for digging.

Meadow voles construct nest cavities of dry grass 6-8 inches in diameter, which are usually located on the surface of the ground or under old boards, discarded metal, logs, or other such cover. Some nests may be in shallow burrows underground.

Voles are herbivores. They eat seeds as well as leaves and stems of grasses and sometimes other green vegetation and occasionally, roots and bulbs. Voles chew grass to form surface runways in turf areas, and they gnaw on the trunks and roots of various trees and ornamental plants. Gnawing is what rodents like to do. Voles may also take advantage of spilled seeds from bird feeders.

The damage of moles and voles is easily distinguished. Moles excavate tunnels just below the surface as they forage for soil insects and worms, and this interferes with mowing. Voles remain primarily aboveground, forming 2-inch-wide surface runways, which may go unseen until winter snow melts. Vole damage to turf is largely cosmetic and the damage may repair itself over time, however, the damage to trees and shrubs can be serious.

Mole management primarily centers on two methods: trapping and using poison mole baits. Traps work, but it takes practice to be proficient. The most effective poison bait is a gel-type "worm" placed inside a mole run; the mole consumes the poison worm and later dies. The product typically contains the active ingredient bromethalin.

Vole management options include using cultural practices, the use of traps (minor infestations), and the careful use of rodenticides.

Eliminate weeds and dense ground cover around lawns, which will reduce the capacity of these areas to support voles. Also, mow your lawn regularly. Avoid using excessive mulch around trees and shrubs, and maintain an air gap (no mulch) of 2-3 inches around trunks and basal stems.

Mouse snap traps can be used to control a small population by placing the trap perpendicular to the runway with the trigger end in the runway. The traps can be baited with a peanut butter-oatmeal mixture or apple slices. Fall and late winter are periods when many vole species are easiest to trap.

If you elect to use a rodenticide, extreme caution must be exercised. These are mostly formulated as baits to be placed into burrow openings, but remember that other animals (including dogs and cats) dig for and prey on voles and will become exposed to baits if not used sparingly and properly. Always consult state regulations, and use all pesticides strictly according to label directions.

For more information on moles, access Purdue Extension publication ADM-10-W, Moles, online at www.edustore.purdue.edu. Indiana Department of Natural Resources also has information available on moles at https://www.in.gov/dnr/fish-and-wildlife/wildlife-resources/living-with-wildlife/eastern-mole/.