The mole is a small mammal belonging to the family Talpidae that spends nearly its entire life underground. These insectivores are commonly found in residential landscapes, where their constant tunneling in search of food creates a unique conflict for homeowners. The presence of a mole signals a debate between natural ecological benefits and the aesthetic and structural damage they can inflict on maintained turf and gardens. Understanding this conflict requires looking past the visible disruption to appreciate the animal’s role in the soil ecosystem.
Ecological Benefits of Moles
Moles are not vegetarians; they are specialized insectivores whose diet primarily consists of earthworms, insect larvae, and grubs. A single mole can consume a significant amount of prey, with a typical 5-ounce mole eating up to 50 pounds of insects and grubs in a year. This voracious appetite acts as a form of natural pest control, managing populations of insects that might otherwise damage plant roots.
The physical act of tunneling also provides important benefits to the soil structure. As moles move through the earth, they aerate the soil, which helps to alleviate compaction and improves water infiltration. This mixing of soil layers redistributes organic matter and nutrients, making them more available for plant roots. The resulting well-aerated soil supports a healthier microbial ecosystem and promotes better root growth for vegetation.
Visible Damage to Landscapes
While their underground work is beneficial, the physical evidence of mole activity is often unwelcome in a manicured yard. Moles create two primary types of tunnels that cause visible damage to the landscape.
The first type is the surface feeding tunnel, which appears as raised ridges of soil that can be easily compressed underfoot. These shallow runways are created as the mole hunts for prey just below the grass line, often dislodging grass roots and causing the turf above to dry out and die in patches.
The second form of damage involves the molehill, a conical or volcano-shaped mound of loose dirt. These mounds result from the mole excavating soil from deeper, permanent tunnels and pushing it up to the surface. Molehills can range from 2 to 12 inches tall and disrupt the lawn’s surface and can interfere with mowing. Extensive tunneling can destabilize the ground in garden beds, and the resulting air pockets around roots can cause plants to suffer or perish.
Differentiating Moles from Other Yard Pests
Accurately identifying the animal causing the damage is the first step toward effective management, as control methods differ between species. Moles are easily confused with gophers and voles, but their damage patterns and diets are distinct. Moles are insectivores, meaning the damage to plants is an unintended byproduct of their hunting, not their primary goal.
In contrast, gophers and voles are herbivores that actively consume plant material, roots, and bulbs. Gopher mounds are typically crescent or fan-shaped, with the entrance hole plugged off to the side of the mound. Molehills, however, are symmetrical and volcano-shaped, with the dirt pushed up through a central opening. Voles, often called meadow mice, create shallow surface trails or “runways” through the grass but do not construct large mounds of earth.
Practical Strategies for Coexistence and Management
When balancing the mole’s ecological advantages with aesthetic concerns, homeowners have several options for management that prioritize non-lethal methods.
One approach is to reduce the primary food source by treating the lawn for grubs using beneficial nematodes or milky spore disease. While this may make the area less appealing to moles, it is important to note that they also feed heavily on earthworms, and eliminating grubs may only offer temporary relief.
For targeted protection, installing physical barriers can be a long-term solution. A wire mesh or hardware cloth can be buried vertically around garden beds to a depth of 24 to 30 inches, with a portion extending above the ground to prevent moles from entering. Another option involves using castor oil-based repellents, which may deter moles from an area for a short time. If the activity is persistent and severe, professional management or the use of scissor or choker-loop traps, set in active tunnels, is often the most reliable method for removal.