A mole infestation can quickly ruin the appearance of a manicured lawn, leaving behind a network of unsightly tunnels and mounds. Moles cause damage by constantly tunneling beneath the surface, which uplifts sod and creates spoil heaps. Addressing the problem effectively requires identifying the pest correctly and then applying targeted control methods.
Identifying the Pest: Mole vs. Vole vs. Gopher
Correct identification of the burrowing animal is the first step, as control strategies differ significantly. Moles are insectivores, primarily seeking earthworms and insect larvae, such as grubs, as they tunnel just below the surface. Their signature sign is the raised ridge or surface runway that snakes across the lawn. They also create volcano-shaped mounds of dirt, called molehills, when pushing excavated soil from their deeper tunnels.
Voles, often called meadow mice, are herbivores and rodents that damage plants by feeding on roots, bulbs, and bark. Their activity is characterized by small, open-entry holes roughly one to one-and-a-half inches in diameter, often connected by visible surface runways. Gophers, also herbivores, create mounds that are typically fan-shaped or crescent-shaped and have a visible dirt plug sealing the main tunnel entrance.
Effective Lethal Methods: Trapping and Baiting
Trapping is the most reliable method for eliminating moles and requires placement in an active runway. To confirm an active tunnel, press down a small section of a raised runway and check it after 24 hours; if the ridge is pushed back up, the mole is using that path. Scissor, harpoon, and choke-style traps are effective and designed to be set directly over the compressed section of the active tunnel. Correct placement ensures the mole triggers the mechanism while attempting to reopen the route.
Safety is paramount when handling and setting these traps, as they employ powerful springs and sharp components. The trap must be firmly anchored in the soil to ensure a quick and humane kill. Traps should be checked frequently and removed promptly once a mole is captured.
Toxic baits offer an alternative lethal option, but they must be mole-specific because moles do not consume the grain-based baits used for rodents. Modern mole baits are often shaped like synthetic worms or grubs to mimic their natural prey. One common active ingredient is Bromethalin, a neurotoxin that disrupts the central nervous system. Another option is Zinc Phosphide, which releases toxic gas when reacting with stomach acids.
Because moles are sensitive to foreign scents and soil disturbance, baits must be applied carefully into the underground runway using a small hole or probe, and the entry point must be sealed afterward. Strict adherence to safety labels is necessary, as these chemical agents pose a significant risk to non-target animals, including pets and wildlife, if they are not confined to the underground tunnel system.
Exclusion and Non-Lethal Deterrents
Preventing moles involves making the habitat less appealing, often by reducing their food sources. While moles primarily eat earthworms, they also consume white grubs and other insect larvae. Applying specific grub control treatments can remove a portion of the mole’s diet, encouraging them to forage elsewhere. Limiting excessive lawn watering can also cause earthworms to move deeper into the soil, making them less accessible.
Non-lethal repellents are another control strategy, with castor oil-based products being the most common. When applied to the lawn and watered in, the castor oil creates an unpleasant environment that moles find undesirable. Sonic or vibratory deterrents are also available, but their effectiveness is variable and often short-lived as moles may eventually habituate to the disturbance.
For targeted protection of garden beds or small areas, physical exclusion is the most reliable long-term solution. This involves installing an underground barrier, such as galvanized hardware cloth or wire mesh, around the protected area. The barrier should extend at least 24 to 36 inches below the soil surface to prevent moles from tunneling underneath. For added security, the bottom edge of the mesh can be bent outward into an “L” shape, which deters the mole as it attempts to dig past the obstruction.