Discovering mounds of soil scattered across a carefully manicured lawn is a common and often frustrating experience for homeowners. These unsightly mounds are the work of moles, subterranean insectivores that spend nearly their entire lives tunneling through the earth in search of food. While these creatures play a beneficial role in aerating soil and controlling grub populations, their surface-level activity can cause significant cosmetic damage and disrupt the delicate root systems of grass.
Identifying True Mole Mounds
It is crucial to distinguish mole mounds from the damage caused by other pests, such as voles or gophers. Moles are insectivores, meaning their diet consists primarily of grubs, worms, and insects found within the soil. As they tunnel just below the surface in search of this food, they create distinct volcano-shaped mounds of soil. These mounds are typically more conical and have a central opening where the animal pushed the dirt upward, unlike the random surface tunnels left by rodents that feed on vegetation.
The Biology Behind the Damage
Moles possess powerful, paddle-like forepaws designed for digging, allowing them to excavate soil at an astonishing rate. An individual mole can create up to 100 feet of new tunnel in a single day. The mounds are formed when the mole pushes the excavated soil to the surface to create a deeper runway or to exit its tunnel system. Because their primary sensory world exists underground, moles are not intentionally trying to ruin a lawn; they are simply navigating their environment and feeding on the grubs that often attract them to residential lawns.
Impact on Lawn Health
The primary damage caused by moles is aesthetic rather than structural to the grass itself. The raised ridges of their shallow tunnels can tear up patches of grass, creating brown, wilted areas where the roots have been severed. Furthermore, the soil mounds smother the grass directly beneath them, killing the blades and leaving behind bare patches. While the mounds indicate active tunneling, the real threat to the lawn often comes secondary, as animals like voles use these runways to feed on grass roots and seeds.
Differentiating Moles from Mounds
Not all mounds in a yard are created by moles, and understanding the difference is key to effective management. Mole mounds are typically symmetrical and granular, resembling a small volcano. In contrast, gopher mounds are often crescent or horseshoe-shaped and feature a fan-like pattern of soil surrounding the plug. Additionally, while mole tunnels are shallow and raised, gopher tunnels are deeper and cause the ground to sink rather than bulge. Correct identification ensures that the appropriate control method is applied.
Management and Control Strategies
Controlling a mole population requires patience and a strategic approach, as trapping is currently the most effective and humane method of elimination. Successful trapping involves locating active tunnels, which can be identified by flattening a section of ridge and checking back in 24 hours to see if it has been re-raised. It is generally ineffective to attempt to flood tunnels or use repellents, as moles are highly adapted to living in saturated soil and are not driven away by simple deterrents.
When to Seek Professional Help
For homeowners with large properties or persistent infestations, consulting a professional pest control expert or a specialized wildlife removal service may be the most efficient solution. These professionals have the experience to quickly locate primary runs and deploy traps correctly. They can also provide advice on reducing the grub population in the soil, which can make the property less attractive to moles seeking food, thereby offering a long-term solution to the problem.
