Moles are small subterranean insectivores belonging to the Talpidae family, whose presence is detected by the damage they cause to lawns and gardens. They spend nearly all their lives underground, creating extensive tunnel systems for travel and foraging. The most visible signs of their activity are the raised ridges of soil (surface feeding tunnels) and volcano-shaped piles of dirt, known as molehills, created when they push soil from deeper tunnels to the surface. It is important to distinguish this damage from that of voles or gophers, as treatment methods differ significantly. Voles create small, open burrow holes and surface runways, while gophers create crescent or kidney-shaped mounds featuring a plugged hole, unlike the circular molehill.
Non-Lethal Deterrence Methods
Non-lethal methods focus on making the environment unattractive to moles, encouraging them to leave the area without causing harm. Castor oil-based products are common deterrents, available in liquid and granular forms. The castor oil coats the moles’ food sources, causing an upset stomach and making the treated area unappealing for foraging. Liquid repellents must be watered deeply into the lawn, often requiring significant watering before and after application to ensure soil penetration. Treatments typically last 30 to 90 days before reapplication is needed.
Another approach uses sonic or vibrational stakes, which emit sound waves or vibrations into the soil. The goal is to disturb the mole’s sensitive hearing and touch, prompting them to relocate. However, the effectiveness of these electronic devices is widely debated, and moles may become accustomed to the noise over time.
Physical Removal Through Trapping
Physical trapping is generally considered the most reliable and effective method for immediate mole removal. The success of trapping depends entirely on correctly identifying and placing the trap in an active, main tunnel, rather than a temporary feeding tunnel. A main runway can be identified by pressing down on a raised tunnel section with your heel; if the tunnel is pushed back up within 12 to 24 hours, it indicates an active, regularly used path. Moles use deep tunnels as highways to travel between feeding areas, and setting a trap here yields the highest success rate.
Common trap types include the scissor trap, the harpoon or spear trap, and the choker loop or tunnel trap, all of which are designed to be lethal. The scissor and harpoon traps are placed above the compressed tunnel, with a trigger pan resting on the soil, which activates the mechanism when the mole attempts to repair the disturbance. Scissor traps close with a pinching action, while harpoon traps drive tines down into the tunnel. Choker loop traps are inserted directly into the tunnel opening and use a spring-loaded loop that closes around the mole. Proper placement requires firmly anchoring the trap legs and ensuring the trigger mechanism is set to be highly sensitive to the mole’s movement, which is accomplished by carefully following the manufacturer’s instructions.
Chemical Control Using Baits
Chemical control involves placing toxic baits directly into the mole’s active tunnel system to eliminate them. These baits are typically designed to resemble the mole’s natural food, such as earthworms or grubs, which are their primary diet. One common active ingredient in mole baits is bromethalin, a potent neurotoxin, while others may use zinc phosphide, which produces a toxic gas upon ingestion. The bait must be placed deep within an active tunnel to minimize the chance of non-target animals finding it.
A significant concern with chemical baits is the risk of secondary poisoning to pets, wildlife, and children. Predators like owls or foxes can suffer toxic effects if they consume a poisoned mole. The label instructions must be followed exactly to reduce the risk of accidental exposure to non-target species.
Preventing Future Infestations
Long-term management focuses on making the area less hospitable to moles to prevent their return after initial removal. Since moles are primarily attracted by a consistent food supply, reducing the population of grubs and soil insects can make the area less appealing. This can be achieved through the application of beneficial nematodes, which target and kill grubs, or by using insecticides. However, since moles also consume beneficial earthworms, eliminating all food sources is impractical and potentially detrimental to soil health.
Another effective prevention strategy is the installation of physical barriers to block their entry into targeted areas. Hardware cloth or wire mesh can be buried vertically around the perimeter of flower beds or vegetable gardens. For this barrier to be effective, it should extend at least 12 to 24 inches deep into the soil and bend outward at the bottom to deter burrowing underneath. Additionally, maintaining a well-drained lawn and avoiding excessive watering helps, as moles prefer moist, loose soil for easier digging.