Groundhog holes are large, roughly circular burrow openings typically 10 to 12 inches in diameter, almost always accompanied by a conspicuous mound of freshly excavated dirt fanning out from the entrance. They are among the most recognizable animal burrows in eastern North America, and once you know what to look for, they are hard to mistake for anything else. The challenge is that groundhogs dig more than one entrance, and the secondary openings look quite different from the main one.
The Main Entrance
The primary entrance to a groundhog burrow is the one most people notice first, because the animal pushes a substantial amount of soil out of it during excavation. Look for a hole roughly the width of a dinner plate, ranging from about 10 to 12 inches across. The opening itself is usually round or slightly oval, worn smooth around the edges from repeated traffic. Groundhogs are stocky animals that can weigh 10 pounds or more, so the hole has to be wide enough for them to pass through comfortably.
The most distinctive feature of the main entrance is the dirt mound. Groundhogs excavate their tunnel systems by pushing loose soil out behind them, and most of that soil ends up piled in a broad, crescent-shaped fan in front of the primary opening. This mound can be two feet wide or more and several inches high. In freshly dug burrows, the soil will look loose and recently turned. In older, established burrows, the mound may be partially covered by grass or weeds but still visibly raised compared to the surrounding ground.
If you spot a large, clean hole with a big pile of dirt beside it and no obvious debris or plant matter plugging the entrance, you are almost certainly looking at a groundhog’s front door.
Secondary and Escape Holes
Most groundhog burrow systems have between two and five openings, and the secondary holes look nothing like the main entrance. These are sometimes called “plunge holes” because the groundhog uses them to dive underground quickly when a predator is nearby. They tend to be slightly smaller, often 8 to 10 inches across, and they sit flush with the ground or are tucked into vegetation. The critical difference is the dirt mound: secondary entrances have little to no excavated soil around them. The groundhog digs these from the inside out, pushing the dirt back through the tunnel system rather than out the hole, so the opening can be surprisingly hard to spot.
Escape holes are often located 15 to 25 feet or more from the main entrance, sometimes on the opposite side of a garden bed, a stone wall, or a slight rise. They may be partially hidden under bushes, against a foundation wall, or among tall grass. If you find a main entrance with a big dirt mound, it is worth walking the surrounding area carefully. Stepping into an unmarked escape hole while mowing a lawn is a common and unpleasant surprise.
Where Groundhogs Prefer to Dig
Knowing where to look is almost as useful as knowing what the holes look like. Groundhogs strongly prefer well-drained soil, which means they tend to dig on gentle slopes, hillsides, elevated berms, and raised ground along fence lines or roadsides. Waterlogged or heavy clay soil discourages them, so flat, low-lying areas with poor drainage are less likely to have burrows.
They also love structural edges. The base of a shed, the foundation of a house, a retaining wall, a rock pile, a brush heap, the edge of a concrete patio: any place where a solid surface meets soft ground is prime groundhog real estate. The structure provides overhead protection and reduces the amount of digging needed to create a secure roof for the tunnel. If you find a hole right at the base of a building or along a stone wall, groundhog should be high on your list of suspects.
In more rural settings, groundhogs commonly burrow at the edges of farm fields, along hedgerows, and in meadows or pastures. They prefer to be near their food supply, so a burrow within easy walking distance of a vegetable garden, a clover field, or a patch of alfalfa is very typical. They are herbivores that feed during the day, and they rarely stray far from a burrow entrance while foraging.
How Deep and Extensive Is the Tunnel System
What you see on the surface is only a fraction of the story. A typical groundhog burrow extends two to five feet below ground and runs horizontally for 15 to 25 feet, though some large, well-established systems have been measured at 40 feet or more. The tunnel connects the main entrance to the secondary openings and usually includes one or more chambers: a nesting chamber lined with dry grass where the groundhog sleeps and hibernates, and sometimes a separate latrine area.
The tunnels themselves are roughly six inches in diameter, slightly smaller than the entrances because the groundhog does not need as much clearance once it is underground. The soil removed during excavation can be substantial. Estimates suggest that a single groundhog may move several hundred pounds of dirt in the process of building a complete burrow system, which explains those large mounds at the main entrance.
Older burrows that have been used for multiple seasons tend to be more complex, with additional side tunnels and expanded chambers. Groundhogs sometimes abandon a burrow and dig a new one nearby, which means properties with a long history of groundhog activity can have a patchwork of old and new holes scattered across the landscape.
Telling Groundhog Holes Apart from Other Animal Holes
Several other animals dig burrows in the same areas where groundhogs live, and distinguishing among them comes down to a handful of details.
- Rabbit burrows: Much smaller, typically four to five inches across. Rabbits in North America (eastern cottontails in particular) rarely dig elaborate tunnel systems the way European rabbits do. A rabbit hole in a yard is usually a shallow scrape or a short, narrow tunnel, nothing close to the dinner-plate size of a groundhog entrance.
- Skunk dens: Skunks sometimes dig their own burrows, but they more often take over existing holes dug by other animals. A skunk-occupied hole may be groundhog-sized, but the giveaway is smell. A strong musky odor near the entrance strongly suggests a skunk. Skunks also tend to leave small, cone-shaped holes in lawns from digging for grubs, which groundhogs do not.
- Chipmunk holes: About two inches in diameter, clean and round, with no dirt mound at all. Chipmunks carry excavated soil away from the entrance in their cheek pouches to avoid attracting attention. If you see a small, tidy hole with no debris around it, that is a chipmunk, not a groundhog.
- Rat burrows: Two to three inches across, often found along walls, foundations, and in trash-strewn areas. The openings tend to look greasy or worn, and the runways leading to them may be visible as narrow, beaten-down paths in the soil or grass.
- Fox or coyote dens: Can overlap in size with large groundhog holes, sometimes because the fox has enlarged an old groundhog burrow. Look for tracks, scat, and prey remains (feathers, bones) near the entrance. Groundhog entrances have none of that; at most you will see some chewed plant stems nearby.
The combination of a 10-to-12-inch opening, a large dirt mound, and a location in well-drained soil near a food source is strongly diagnostic for groundhog. When any of those features are missing, consider the alternatives above.
Signs That a Burrow Is Actively Occupied
Finding a hole that looks right does not necessarily mean a groundhog is currently living in it. Burrows get abandoned, taken over by other animals, or left unused for a season. A few clues help you figure out whether the burrow is active.
Fresh dirt is the most reliable indicator. If the soil on the mound looks recently turned, loose, and free of plant growth, the groundhog is still excavating or maintaining the tunnel. Established burrows where the groundhog is in residence also show worn, smooth edges around the entrance from daily use. You may notice tracks in the dirt mound or along paths leading to and from the hole. Groundhog tracks show five toes on the front feet and four on the back, though you often just see a general scuffing pattern rather than clean prints.
Look at the vegetation around the entrance. An active burrow usually has a clearing of short or trampled vegetation immediately surrounding it, because the groundhog flattens the area with regular traffic. Nearby plants may show signs of browsing: cleanly clipped stems, missing leaves low to the ground, or partially eaten garden crops. Groundhogs are not subtle feeders. If your tomato plants are being systematically stripped and there is a large hole 20 feet away, the case is fairly strong.
Conversely, a hole with spider webs across the opening, leaves or debris accumulated inside, and undisturbed vegetation growing right up to the edge has probably been vacant for weeks or months. Old abandoned burrows eventually collapse or become plugged with soil, but that process can take a long time, so empty burrows may persist for a year or more before they disappear.
Damage and Safety Risks
Groundhog burrows are an engineering problem for homeowners and farmers in a way that smaller rodent holes are not. The tunnel system undermines the soil, and that can cause visible settling or even collapse of the ground above it. When burrows run under a driveway, a sidewalk, a patio, or a building foundation, the resulting voids can lead to cracked concrete, shifted pavers, or in serious cases, structural damage to a foundation wall. Water flowing into the tunnels during rain can accelerate erosion underground, washing out soil and creating larger voids than the original tunnel.
On farms, groundhog holes are a genuine hazard for livestock. A horse or cow stepping into an unmarked burrow entrance at speed can break a leg. Agricultural equipment can also be damaged when a wheel drops into a hidden hole. For these reasons, farmers tend to take groundhog activity seriously and address it early rather than waiting to see if the animal moves on.
In residential yards, the more immediate annoyance is usually the garden damage rather than the structural risk. A single groundhog can devastate a vegetable garden in a matter of days. They eat a wide range of plants, with a particular fondness for beans, peas, lettuce, clover, and squash. They also gnaw on ornamental plantings and occasionally chew on wooden deck supports or siding, though this behavior is less common than the garden raiding.
What to Do When You Find Groundhog Holes on Your Property
If you have confirmed that the holes are from a groundhog and you want the animal gone, you have several practical options, each with trade-offs.
Exclusion fencing is often the most effective long-term solution, especially for protecting a garden. A fence needs to be at least three feet tall and should extend about a foot underground in an L-shape (bent outward) to prevent the groundhog from digging under it. Groundhogs are decent climbers, so floppy, unsecured tops that wobble when the animal tries to scale them can help. Hardware cloth with openings no larger than two inches by two inches works well.
Live trapping is legal in most areas, though regulations about relocating wildlife vary by state and sometimes by county. A large cage trap baited with cantaloupe, apple slices, or fresh vegetables placed near the main entrance can be effective. Relocated groundhogs need to be released several miles away, ideally in suitable habitat, or they may find their way back. Check local wildlife regulations before trapping; some jurisdictions require a permit or prohibit relocation entirely.
Fumigation with gas cartridges is another common approach, particularly on farms. These devices are placed inside the burrow and produce carbon dioxide or sulfur dioxide gas that fills the tunnel system. Effectiveness depends on sealing all secondary entrances first so the gas does not simply vent out. This method is typically more practical in open-field situations than in residential yards near buildings, because of the fire risk from the smoldering cartridge and the difficulty of locating every escape hole.
Filling the burrows is sometimes tempting but is usually ineffective as long as the groundhog is still present, because the animal will simply re-excavate or dig a new entrance nearby. Once you are confident the burrow is truly abandoned, filling the tunnels with a mixture of soil and gravel and then packing the surface prevents the hole from becoming a hazard or an invitation for a new tenant. For holes near foundations, filling with a concrete or gravel slurry is worth the extra effort to prevent future settling.
Seasonal Patterns and When Burrows Appear
Groundhog activity follows a strong seasonal cycle, and understanding it helps you predict when new holes are most likely to show up. Groundhogs are true hibernators. They enter their burrows in late fall, typically October or November depending on latitude, and emerge in late January or February. The famous Groundhog Day tradition on February 2 reflects this real biological timing, though the animal’s emergence has nothing to do with shadow-watching and everything to do with hormonal cycles tied to day length.
Most new burrow digging happens in spring and early summer, when young groundhogs born that year strike out on their own and need to establish their own territory. A litter typically includes two to six pups, and each one that survives to independence will dig at least one new burrow system. This means that a property with one groundhog in the spring can end up with several new sets of holes by midsummer. If you are finding fresh holes in June or July, young-of-the-year groundhogs dispersing from a nearby natal burrow is the most likely explanation.
By late summer, digging activity tends to slow down. The groundhog shifts its energy toward eating as much as possible to build fat reserves for hibernation. During hibernation, the burrow entrances remain open but unused, and they gradually accumulate leaves and debris over the winter. A burrow that looks messy and leaf-filled in March may still be occupied; the groundhog is just waking up and has not yet cleaned house. Give it a few weeks of warm weather and check again for fresh dirt and cleared entrances before concluding the burrow is abandoned.