The mole is a small, subterranean mammal that spends its life beneath the soil, using powerful front paws to dig an extensive network of tunnels. As natural insectivores, moles are part of the ecosystem, but their relentless search for food conflicts directly with maintaining a manicured yard. The underground activity of a single mole can quickly transform a pristine lawn into a landscape marred by physical obstructions and functional damage. The primary problems stem from the sheer volume of soil displacement and the creation of their elaborate tunnel systems.
Disruption of Lawn Appearance
The most immediate and visible sign of mole activity is the destruction of a lawn’s uniform appearance. Moles create two primary types of surface disruption. First, deep, permanent tunnels result in volcano-shaped mounds of excavated dirt, known as molehills, scattered across the turf. These piles of loose soil make the yard look messy and require constant cleanup. The second form of aesthetic damage is the creation of shallow feeding tunnels, which appear as raised, meandering ridges just beneath the grass. These surface runs are easily visible as raised lines across the lawn. Walking on a lawn crisscrossed by these tunnels can feel spongy, and the uneven surface makes mowing difficult, often leading to the mower scalping the raised grass blades.
Structural Damage to Roots and Turf
The functional harm caused by tunneling goes deeper than visible surface disruption. While moles do not consume plant material, their burrowing activity indirectly causes significant structural damage to turf and garden plants. As a mole pushes through the soil, it severs or lifts the fine roots of grass and plants from the surrounding earth. This separation leaves the root system suspended in an air pocket or loose soil, disrupting the plant’s ability to absorb water and nutrients. The exposed roots dry out quickly, a process known as desiccation, resulting in large, irregular patches of brown, dying grass across the lawn.
Damage to Landscape Beds
This root disruption can also affect landscape beds. Tunneling may dislodge bulbs or expose the roots of established plants to the air, ultimately leading to their decline.
Facilitation of Secondary Garden Pests
The extensive network of stable, abandoned mole tunnels often compounds issues by creating an ideal habitat for other destructive garden pests. Moles build established subterranean highways that provide easy travel and shelter for small rodents like voles. While the mole is an insectivore that hunts invertebrates, the vole is a true herbivore that actively feeds on plant roots, bulbs, and the bark of young trees. Once voles move into the mole’s pre-dug tunnels, they inflict severe damage to root systems without having to dig their own extensive network. Homeowners may mistakenly attribute the root-eating damage to the mole, when it is the secondary pest taking advantage of the established underground infrastructure.
Weed Germination
Additionally, the constant displacement of deep soil onto the surface in molehills creates patches of exposed, fertile earth. These patches are prime locations for opportunistic weed seeds to germinate and flourish.
Clarifying Mole Diet and Behavior
A common misconception is that moles are attracted to a yard only because of an infestation of grubs, leading many to use grub control products as a solution. However, a mole’s diet primarily consists of earthworms, which are considered beneficial to soil health. Earthworms make up the majority of their food intake, with grubs and other insects being a secondary food source. Because of their high metabolism, moles must consume 70 to 100 percent of their body weight daily, requiring them to constantly tunnel in search of prey. This relentless foraging behavior, not the consumption of plants or roots, is the root cause of the damage to the yard.
Distinguishing Moles and Voles
It is helpful to distinguish the mole, an insectivore, from the vole, a rodent. They cause different types of damage, and control methods effective for one will not be effective for the other.