Moles and voles are common yard pests that damage lawns and gardens. Moles create unsightly mounds and ridges across turf, while voles consume plant material, often killing shrubs and trees. Effective removal requires understanding the specific habits of each animal, as control methods for one are often ineffective for the other.
Identifying the Intruder
The first step in pest control is accurately identifying the animal causing the damage, as their diets and behaviors are distinctly different. Moles are insectivores, primarily feeding on earthworms, grubs, and other soil invertebrates; their tunneling is a search for food. Mole activity is characterized by two signs: volcano-shaped hills of soil (molehills) and raised surface ridges that look like small trails in the lawn.
These surface ridges are temporary feeding tunnels that flatten easily when walked upon. Voles are herbivores, belonging to the rodent family, and they primarily eat plants, seeds, roots, and tree bark. Vole damage is marked by visible, narrow, above-ground runways in the grass, which are consistent paths between their burrows and food sources.
Voles do not create large soil mounds; instead, they leave small, dime-sized burrow openings, often near the base of trees or under dense ground cover. The most destructive vole damage is seen on plants, where they gnaw on the bark, a process called girdling, which can kill young trees and shrubs. Irregular gnaw marks near the soil line or plants clipped clean indicate vole presence.
Eradication Methods for Moles
Trapping is the most reliable method for removing moles, who rarely consume seed-based poisons. Start by identifying an active tunnel: gently flatten a section of a surface run and check 24 hours later to see if the mole has repaired it. Traps must be placed directly into these active tunnels to intercept the mole during its regular travel.
Two common trap designs are the scissor-jaw and the harpoon-style traps. The scissor trap is set by removing a soil plug, inserting the jaws into the tunnel, and replacing soil to block light. The harpoon trap is set over a collapsed section of the tunnel; the mole pushes up to reopen the tunnel, triggering the mechanism.
Handle traps with gloves to prevent transferring human scent, which can cause the mole to reroute its tunnel. Traps should be checked daily and relocated if unsuccessful within 48 to 72 hours, as moles often abandon runs quickly.
Baits
As an alternative, specialized baits target the mole’s insectivorous diet. These baits are formulated to resemble earthworms, the mole’s natural food source. The active ingredient is often bromethalin, a non-anticoagulant neurotoxin.
This toxicant disrupts the mole’s ability to convert food to energy, leading to death within one to three days after a single feeding. Baits must be carefully placed deep inside active tunnels using a probe, never left on the surface where non-target animals could access them. Effectiveness is confirmed by the cessation of new tunneling activity.
Control Strategies for Voles
Vole control relies on managing their habitat, using physical barriers, and targeted baiting. Since voles are herbivores, they readily consume grain-based rodenticides. Toxic baits, often containing zinc phosphide or an anticoagulant, should be placed in protected bait stations or directly into the visible surface runways.
Bait stations limit access to the poison by pets and other wildlife while allowing voles to feed freely. Standard mouse snap traps are effective for small infestations when placed perpendicular to the runway. Traps can be baited with peanut butter, oatmeal, or apple slices to increase attraction.
Exclusion and Habitat Management
Exclusion is a long-term method for protecting vulnerable plants, especially in winter. Young trees and shrubs should be protected with cylindrical guards made of quarter-inch wire mesh or hardware cloth. These guards must extend above the anticipated snow line and be buried at least six inches into the soil to prevent burrowing underneath.
Voles seek shelter, so removing dense ground cover is an important preventative measure. Regularly mowing the lawn and removing excess mulch, brush piles, or fallen leaves eliminates the protective cover voles prefer for nesting and travel. Avoid piling mulch directly against tree trunks, which creates a hidden feeding location.
Long-Term Yard Protection
Long-term yard protection focuses on making the environment less inviting to both pests after initial control. For moles, reducing their food source is an effective deterrent. Applying beneficial nematodes or milky spore disease targets the larval stage of insects like Japanese beetles, a component of the mole’s diet.
Reducing soil moisture by cutting back on excessive watering also discourages moles. Earthworms and grubs are drawn to saturated soil, and moles find it easier to tunnel in soft, moist ground. A drier lawn is naturally more resistant to mole activity.
Physical Barriers
Physical barriers offer defense for garden beds and ornamental areas against both burrowing animals. Install a trench barrier around the perimeter of a vulnerable area, lined with galvanized hardware cloth, to prevent access. The trench should be at least two feet deep.
The hardware cloth should be bent outward at a 90-degree angle at the bottom to discourage digging underneath, with a few inches remaining above ground level. Regular maintenance that removes debris and clutter is a preventative measure against voles. Keeping grass trimmed short and clearing leaf litter reduces hiding places, making the yard a less desirable habitat.
Vigilance and immediate action upon seeing fresh activity are the best defense against a new infestation for both pests.