Groundhogs, also known as woodchucks, are known for their complex underground tunnel systems. These mammals spend much of their lives in burrows, which serve various purposes for their survival. These networks provide shelter, facilitate raising young, and enable hibernation.
More Than Just a Hole
Groundhog burrows provide shelter from predators and harsh weather. They also serve as safe havens for hibernation and as nurseries for raising their young. Groundhogs use their strong, short front legs with sturdy claws to loosen soil and rocks. While their powerful incisors can assist, they primarily use their claws for digging. Excavated dirt is moved with their mouths and deposited at the main entrance.
A typical groundhog burrow begins with a downward tunnel, then inclines upward before extending horizontally for 15 to 25 feet. This design helps prevent flooding. From the main tunnel, two to three side tunnels often branch off, leading to separate chambers. These chambers serve distinct functions, including sleeping areas, nesting sites, and dedicated latrine areas. Groundhogs seal off filled latrine areas and dig new ones as needed.
Groundhog burrow systems can reach total tunnel lengths of up to 65 feet. Most of the year, a burrow is occupied by a single groundhog, except during breeding season when males visit female burrows, or when females raise their litters of four to six kits. Groundhogs often maintain separate burrows for summer use in grassy fields and winter hibernation in wooded areas. Winter burrows are typically deeper, dug below the frost line, and may have only one entrance, which the groundhog blocks with soil to maintain a stable temperature.
Recognizing a Groundhog’s Handiwork
Identifying a groundhog burrow involves specific characteristics. The main entrance typically measures 10 to 12 inches in diameter. This opening usually features a noticeable fan-shaped or crescent-shaped mound of excavated dirt immediately outside. This dirt mound, which can weigh over 275 pounds, indicates a groundhog’s presence.
Beyond the primary entrance, groundhog burrows often have one to four auxiliary entrances or escape tunnels. These secondary entrances are less obvious, as they are excavated from within and lack the tell-tale dirt mound at the surface. Groundhogs prefer to dig burrows in well-drained soil, often near fence lines, under sheds, at the base of trees, or along building foundations, which offer concealment and structural support.
Other signs also indicate a groundhog’s presence. These include worn paths between the burrow and feeding areas, evidence of their herbivorous diet like damaged garden plants with cleanly cut stems, or gnaw marks on wooden structures or trees. Groundhogs are most active during early morning and late evening, so sightings near a suspected burrow can confirm occupancy. The presence of groundhog droppings, about 1/2 to 3/4 inch long and resembling thick, short sausages, is another sign.