Moles are insectivores whose constant tunneling activity can cause significant damage to lawns and gardens. Infestation is identified by two primary signs: raised ridges, which are shallow feeding runs, and cone-shaped dirt piles called molehills, marking the entrance to deeper runways. Identifying these features helps differentiate mole damage from that of other burrowing pests, ensuring the correct control method is chosen. A single mole can create a complex network of tunnels, making their removal a challenge that requires targeted strategies.
Physical Removal: Trapping Techniques
Trapping remains the most reliable and effective method for removing moles once activity is established. Success depends on locating the primary tunnels moles use repeatedly for travel. To identify these main runways, flatten a section of the raised tunnel and check it 24 hours later; if the tunnel is pushed back up, it is active and ideal for a trap.
There are several types of lethal traps designed for mole removal, including the harpoon, scissor, and choker loop models. Harpoon traps are pressed into the soil above a flattened tunnel, while scissor and choker loop traps are set directly within a small excavated section of the runway. Regardless of the type chosen, precise placement is essential to ensure the mole triggers the mechanism as it travels through its repaired tunnel.
Wear gloves when handling traps to prevent leaving human scent, as moles are sensitive to foreign odors and may avoid a tainted device. Traps should also be anchored securely to the ground to prevent dislodgement by the mole or non-target animals. Checking the traps at least once daily allows for prompt removal and resetting.
Chemical Control: Baits and Fumigants
Chemical options for mole control fall into two main categories: toxic baits and fumigants. Toxic baits are manufactured to mimic the mole’s natural food source, since moles primarily consume live invertebrates rather than grain or seed. Modern commercial baits often use active ingredients like bromethalin or zinc phosphide, which are neurotoxins or acute toxicants.
These baits must be placed directly into active mole tunnels to ensure the mole encounters them underground. Bromethalin-based products work as a nerve poison, while zinc phosphide reacts with stomach acids to release phosphine gas. Caution must be exercised with all toxic baits, as they pose a significant risk of secondary poisoning if not applied correctly and kept entirely below the surface.
Fumigants, such as ignitable gas cartridges, produce toxic gases, typically carbon monoxide, when ignited. For these products to be effective, the entire tunnel system must be sealed completely, trapping the gas inside to asphyxiate the mole. However, moles create extensive, complex tunnel systems that are difficult to seal entirely, meaning fumigants are often ineffective for controlling an infestation. These products must only be used according to the manufacturer’s instructions and local regulations.
Non-Lethal Deterrents and Habitat Modification
Non-lethal methods aim to make the yard less appealing to moles. One common approach involves applying a castor oil-based repellent. Moles find the scent and taste of castor oil unpleasant, as it irritates their digestive system if ingested. The repellent must be applied across the entire affected area and followed by deep watering to carry the solution into the soil profile.
Another strategy focuses on reducing the mole’s food supply, particularly white grubs. Beneficial nematodes, organisms that parasitize grub larvae, can be introduced to the soil as a biological control. While this reduces the grub population, earthworms constitute the largest portion of a mole’s diet, and eliminating grubs alone may not be enough to deter moles.
For permanent exclusion, physical barriers can be installed around specific areas. This involves burying galvanized hardware cloth or wire mesh at least 24 to 30 inches deep, with the bottom edge bent outward in an L-shape to prevent tunneling underneath. Sonic or vibrating stakes are also marketed as deterrents, but scientific evidence shows that moles quickly habituate to the noise and vibration, often tunneling around the device.
Addressing Common Misconceptions
Homeowners often try home remedies that are ineffective or hazardous. Placing chewing gum in a tunnel will not clog a mole’s digestive tract, as moles are insectivores. Similarly, flooding a tunnel system with a hose is rarely successful because moles can tunnel faster than the water can fill the extensive network.
The use of mothballs is also discouraged because the strong odors do not effectively repel moles. Furthermore, applying an insecticide to kill grubs is an ineffective mole control strategy. This application can kill beneficial earthworms, which are the mole’s primary food source, and may also be illegal if the insecticide label does not specifically allow for mole control.