Molehills and shallow, raised tunnels in a lawn can be frustrating for homeowners. Before reacting with lethal measures, understand the animal. The mole is a subterranean mammal belonging to the order Eulipotyphla, meaning it is an insectivore, not a rodent like a mouse or gopher. Moles spend nearly their entire lives underground, using their powerful, paddle-like forefeet to “swim” through the soil in search of food. This constant tunneling, while visually disruptive, provides significant environmental benefits, which are lost when the animal is removed.
The Mole’s Role in Soil Ecosystems
The extensive tunnel systems moles create are far from a simple nuisance; they actively improve the structure and health of the soil. As they dig, the tunnels naturally aerate the earth, allowing air and water to penetrate deep below the surface. This process relieves soil compaction, which is beneficial for plant root growth and improves overall water absorption and drainage.
Moles also function as natural biocontrol agents by consuming large quantities of soil-dwelling invertebrates. Their diet consists primarily of earthworms, but they also prey on destructive pests such as white grubs (the larvae of Japanese beetles) and other insect larvae. Moles must eat a significant amount daily, often 70 to 100 percent of their body weight, meaning they constantly manage local pest populations.
The burrowing activity also contributes to nutrient cycling by mixing different soil layers. Moles bring subsoil closer to the surface, where plants can access nutrients that were previously unavailable. Removing a mole eliminates this natural, continuous soil management, potentially requiring the use of chemical pesticides to control grubs or manual aeration techniques.
Why Lethal Control Methods Are Often Counterproductive
Using lethal methods such as traps, poisons, or gassers often fails to provide a lasting solution to mole activity. This failure is largely due to a phenomenon known as the “vacuum effect”. When a mole is successfully removed from a territory, the resources that attracted it—plentiful food and suitable habitat—remain available.
The empty territory quickly attracts a new mole from adjacent areas, which moves in to take advantage of the vacant resources. This makes lethal control a continuous, self-defeating cycle that requires repeated effort. The removal simply creates a temporary dip in activity before the population rebounds.
Furthermore, lethal control introduces significant risks to non-target species, pets, and even people. Poisons formulated for moles can harm dogs or cats that encounter the bait or the poisoned mole. Traps, particularly those placed in surface tunnels, pose a hazard to children and other wildlife. Misidentification is also common, as the damage may be caused by voles or gophers using mole tunnels, meaning a lethal mole trap will not solve the actual problem.
Humane and Effective Methods for Control
Instead of lethal measures, homeowners can use humane strategies focused on deterring the mole and making the area undesirable. One highly effective method is habitat modification, which involves reducing the mole’s primary food source. Treating the lawn for white grubs will eliminate a portion of the mole’s diet, encouraging the animal to move on to a location with better foraging opportunities.
Physical barriers offer a permanent solution for protecting specific areas like garden beds. Burying galvanized hardware cloth or wire mesh 24 to 30 inches deep around the perimeter of a garden will prevent moles from burrowing into the protected space. The barrier should extend a few inches above the ground to prevent the mole from simply tunneling over it.
Repellents are a non-lethal way to encourage the mole to leave without causing harm. Products containing castor oil are commonly used, as the substance makes the mole’s food source taste unappealing and irritates its digestive system. For the repellent to be successful, it must be watered deeply into the soil to saturate the tunnels and applied consistently to drive the mole out of the area.
In situations where direct removal is necessary, live-trapping offers a humane option. A simple pit-fall trap can be constructed using a 2- to 5-gallon bucket buried beneath an active tunnel. If a mole is caught, it must be relocated quickly to a suitable natural habitat, but local regulations on wildlife relocation must be checked before attempting any trapping.