Groundhogs, also known as woodchucks, are common burrowing rodents found throughout North America. These animals are known for their ability to excavate extensive underground tunnel systems. Property owners often wonder about their digging capabilities, especially concerning concrete structures. This concern arises from visible burrow entrances near foundations, patios, or sheds, prompting questions about potential damage.
The Truth About Groundhog Digging
Groundhogs cannot chew or dig directly through solid concrete. Concrete is a dense and abrasive material their teeth and claws are not designed to penetrate. Their primary tools, strong claws and continuously growing incisors, are adapted for digging through soil and gnawing on vegetation, not hard construction materials.
Damage to concrete structures is indirect, resulting from groundhog burrowing activities underneath or around them. When groundhogs excavate tunnels beneath concrete slabs, patios, or foundations, they remove supporting soil, creating voids. This undermining of the soil can lead to a lack of support for the concrete, causing it to crack, settle, or even collapse under its own weight or external pressure. Groundhogs often target these areas because the concrete provides a stable “roof” for their burrows and can offer consistent temperatures.
Understanding Groundhog Burrowing
Groundhogs are skilled diggers, thanks to their physical adaptations. They possess muscular bodies, short, powerful legs, and broad, sharp claws suited for moving earth. Their large, chisel-shaped incisors, which grow approximately 1.5 millimeters per week, are used for gnawing on roots and soil, helping to clear their path underground.
A groundhog’s burrow system is a complex network of tunnels and chambers. These burrows serve various purposes, including shelter from predators, hibernation during winter, raising young, and storing food. A typical burrow system can extend 2 to 6 feet deep and range from 20 to 50 feet in length.
Burrows feature a main entrance, often identified by a mound of excavated dirt, and can have anywhere from two to twelve additional openings. These secondary entrances, which may not have visible dirt mounds, function as escape routes from predators. Within the burrow, specific chambers are designated for nesting, waste elimination (latrines), and sleeping.
Preventing Groundhog Damage to Structures
Preventing groundhog damage to structures involves proactive measures to deter their burrowing. One effective strategy is installing exclusion barriers around vulnerable areas such as foundations, sheds, and decks. These barriers involve burying wire mesh or hardware cloth at least 6 to 12 inches deep, with an additional 12 to 24 inches bent outward in an L-shape away from the structure. This design creates a horizontal underground obstacle that frustrates a groundhog’s attempts to dig beneath the barrier.
The mesh material should be heavy-gauge, galvanized wire with openings no larger than 2×3 inches to prevent groundhogs from gnawing through or squeezing past. The fence should also extend at least 3 to 4 feet above ground, with the top portion bent outward at a 45-degree angle or left unstable to deter climbing. Ensure no groundhogs are currently under the structure before installing an exclusion fence, as this could trap them inside.
Modifying the habitat around a property can also discourage groundhogs. Removing brush piles, tall weeds, and other potential hiding spots near structures reduces attractive cover. Keeping grass trimmed and clearing debris can make an area less appealing for groundhog residency.
While various repellents, including natural scents like predator urine, garlic, cayenne pepper, or commercial products, are available, their effectiveness can vary and often provide only temporary relief. These methods require frequent reapplication, especially after rain. For persistent or extensive groundhog activity, contacting a wildlife control professional is often recommended for humane removal and comprehensive prevention strategies.