A mole is a small, subterranean mammal that spends nearly its entire life underground, characterized by a cylindrical body and large, powerful front paws designed for digging. These creatures are insectivores, not rodents, and they play a complex role in the ecosystem of a yard or garden. While mole activity can be frustrating for homeowners due to visible damage to turf, their presence also brings substantial ecological benefits to the soil structure and the management of garden pests. Assessing whether a mole is a beneficial resident or an actual problem in your landscape requires understanding this dichotomy.
Moles as Soil Engineers
The extensive tunneling performed by moles acts as a natural tilling process, fundamentally altering the soil’s physical properties. As the animal “swims” through the earth, it mixes deeper subsoil with the topsoil, which can help redistribute vital nutrients throughout the root zone. This mixing action contributes to a more uniform soil profile, making resources available to a broader range of plant roots.
The creation of subterranean channels is highly beneficial for soil aeration, which is the process of incorporating oxygen into the ground. These tunnels allow fresh air to penetrate layers of compacted soil, supporting the respiration of plant roots and beneficial microorganisms. Improved aeration encourages healthier root growth and enhances the overall microbial activity that drives nutrient cycling in the ecosystem.
Mole tunnels also significantly improve water management within the soil, acting as natural drainage channels. By breaking up dense soil layers and reducing compaction, the tunnels allow water to infiltrate deeper into the ground rather than pooling on the surface. This increased drainage helps prevent waterlogging in heavy or clay-rich soils. The physical disturbance of the soil, while unsightly on the surface, ultimately fosters a more robust and hospitable environment beneath the lawn.
Diet and Garden Pest Management
Moles are insectivores, meaning their diet is composed of living prey found within the soil. The majority of a mole’s diet, often 85 to 90 percent, consists of earthworms, which are its preferred food source. They must consume a large volume of food daily, sometimes eating 70 to 80 percent of their own body weight, due to the high energy demands of constant tunneling.
Despite the focus on earthworms, moles actively seek out and consume many invertebrates considered destructive garden pests. This includes the larvae of insects like Japanese beetles, as well as cutworms, millipedes, and mole crickets. By preying on these subterranean larvae, moles provide a form of natural pest control that helps limit the population of insects that feed on plant roots and turfgrass.
Moles do not intentionally consume plant material, distinguishing them from other yard pests. The common misconception that moles eat roots or bulbs is inaccurate; they are searching for the insects and worms found near those root systems. Therefore, their presence can indicate a healthy invertebrate population, including both beneficial earthworms and potentially harmful pest larvae.
Identifying Mole Activity Versus Other Pests
Moles are often wrongly blamed for problems caused by rodents like voles and gophers. Mole activity is characterized by two distinct signs: volcano-shaped mounds and raised surface ridges. A mole mound is typically symmetrical and conical, formed when the animal pushes soil upward from a deep, permanent tunnel, and often lacks a visible entrance hole in the center.
The more common sign is the presence of raised surface ridges, which are shallow tunnels used by the mole for daily foraging. These temporary “runs” are just below the surface and may cause the ground to feel spongy or soft when walked upon. These ridges are created as the mole pursues earthworms and grubs, not when it is eating plant roots.
Actual plant consumption is characteristic of other burrowing animals. Gophers create crescent or fan-shaped mounds, where the plugged entrance hole is usually visible off to one side of the dirt pile. Voles, which are small rodents, do not leave large mounds but instead create small, clean-cut, open holes and surface runways in the grass. If you observe plants being pulled entirely underground or bulbs being eaten, the damage is almost certainly caused by a gopher or a vole.