By Dr. Susan Hamilton
These mouse-like critters can wreak havoc on your lawn and garden, but control depends upon which you have. So how do you know if you’re fighting moles or voles? Even though similar in habit and about the same size, moles and voles are really very different. They have completely different diets, and they cause different types of damage in your landscape.
Voles are rodents. They are commonly called mice, meadow mice or field mice. They are about 3 inches long, weigh 1 ounce or less and have reddish-brown fur, a short half-inch tail, tiny ears and eyes that are not visible. Of the 23 species of voles in the United States, the pine vole and the meadow vole are the most common for our region.
Voles spend most of their lives above ground, living in and feeding on grasses, although they can chew or girdle saplings at ground level. Tall fescue in orchards and lightly grazed pastures are typical habitats. They are typically much less troublesome than the pine vole, which loves to infest our landscaped gardens.
Pine voles spend most of their lives under the ground in burrows feeding on plant roots. You are more likely to see signs of voles than the voles themselves, but sometimes you may glimpse one scurrying from one planting bed to another. They like living in mulch, leaf and grass piles, and tall ground covers. They love to eat roots of lawn grass, trees and shrubs, flower bulbs and your favorite hostas! In addition, where protective cover is available, voles may girdle the main stem of plants just above the ground. On occasion they will eat bark. Vegetable gardens, ornamental plantings and young trees are all susceptible to vole damage, the most obvious sign of which is a dead or dying plant.
Pine voles are active day and night, searching for food in a home range of about a quarter acre. They seldom venture into exposed places, using instead elaborate tunnel systems that create the all too familiar and unsightly raised ridges in your lawn.
Moles belong to the same family as shrews and bats. They have large paddle-like front feet with prominent claws designed for very efficient digging. They are about the size of chipmunks and can weigh anywhere from three to six ounces. Total length can be six to eight inches. Moles are covered by a soft grey fur, and variegation in color is common with patches of orange or white. Six mole types are found in North America, but the Eastern mole and the grey mole are the most common in Tennessee.
Moles love to eat worms, insect grubs and adult insects. Like voles, moles tunnel in search of food, and in your lawn and landscape beds their tunneling raises the soil into ridges. Moles produce two types of “runways.” One type runs just beneath the surface. These are feeding tunnels and appear as raised ridges running across your lawn. The second type runs deeper and enables the moles to unite the feeding tunnels in a network. It is the soil excavated from the deep tunnels that homeowners find on their lawns, piled up in mounds that resemble little volcanoes. Moles can dig their surface tunnels at a rate of about 18 feet per hour. A mole’s speed through existing tunnels is about 80 feet per minute.
The Difference Between Moles and Voles
Proper identification of these unwanted varmints is critical to control. If you never come face-to-face with the pest, identification must be based on their signs and the damage they do in your landscape. Key indicators for moles are volcano-like mounds of soil. Well-defined, visible runways about two inches wide, at or near the surface indicate voles.
Mole and Vole Prevention Methods
Methods to prevent and control damage for both pests are habitat management, exclusion, repellents, trapping and poison baits. Fumigants are generally ineffective due to the expansive tunnel system and surface holes associated with vole and mole activity. Trapping and poison are lethal to the pests; however, they may not entirely solve your problem. Typically a combination of control methods will produce the best results.
Controlling Moles and Voles
Four primary methods for preventing and controlling landscape damage due to moles and voles are known to work: habitat management, exclusion, repellents, trapping, and poison baits.
Habitat Management: The best way to manage the habitat of moles is to modify their food source. Treating your lawn to control insects and grubs will go a long way in eliminating moles from your landscape. As for voles, eliminating ground cover can be effective in reducing vole damage. Keep lawns adjacent to flower gardens mowed to a short height to discourage voles from moving into gardens to feed. Minimizing the amount of mulch in your landscape and turning the mulch frequently may help discourage voles from establishing tunnel systems. Mulch rings or mounds should be cleared back a minimum of 3 feet from the base of trees. Tilling the garden destroys the tunnels, which can help reduce populations and damage.
Exclusion: Exclusion is a practical method of protecting highly valued flower beds, gardens and trees from vole damage. Voles can be discouraged by installing woven wire or hardware cloth (one-fourth inch or smaller mesh) fences around small flower beds or gardens. The fence should be about 12 inches high and should extend an additional six inches below ground. It should be bent in an inward fashion like an “L.” I’ve had friends who planted their choice ornamental plants in hardware cloth baskets that they made and planted in the ground.
Repellents: Commercial repellents for both varmints are available. Most need to be reapplied to the mounds and tunnels frequently. Homemade repellents such as ammonia, bleach and even chewing gum (Juicy Fruit to be specific) are also touted as working. Since voles feed on roots, there are numerous plants said to be repellents. One is the well-known daffodil. Two lesser known the spring-flowering bulbs Siberian squill (Scilla siberica) and crown imperial (Fritillaria imperialis). The Allium genus of bulbs are also repellents and includes not only garlic, onions, leeks, chives and shallots, but also the ornamental-flowering onions commonly referred to as alliums. The mole plant (Euphorbia lathyris) and castor bean, also known as castor-oil plant (Ricinus communis), are known repellents, but use caution. Both are poisonous, and neither should be grown around pets and small children.
Traps: Traps are designed specifically for killing moles and voles. Where you place the trap is critical to your success. You’ll want to place the trap near the active shallow feeding tunnels. Trapping in the early spring can eliminate pregnant females, effectively nipping in the bud what would be a greater problem later. Place traps at the entrances to tunnels or runways. Bait them with a mixture of peanut butter and oatmeal or sliced apples. The trigger should face the tunnel mouth.
Baits: Talprid is an EPA-approved bait specifically for moles. Whatever you use, you may want to consider using a bait station such as the commercial brand Vole Control Bait Station System to avoid having birds and other non-target animals take the bait.
For More Information
More information is available at the National eXtension website, www.extension.org. Just search for “moles” or “voles.” The Internet Center for Wildlife Damage Management also has helpful information on identifying voles.