Rat holes in a yard are typically 2 to 3 inches wide, smooth around the edges from repeated use, and found along building foundations, under compost bins, or beneath dense vegetation. If you’ve spotted holes matching that description, you’re almost certainly looking at Norway rat burrows, the most common burrowing rat in North America. Here’s how to confirm what you’re dealing with, understand the risks, and close them down for good.
How to Identify Rat Burrows
Norway rats dig burrows with a distinctive look. The entrance is round, about 2 to 3 inches in diameter, and worn smooth by the rats traveling in and out. You’ll typically find them in sheltered spots: along the base of a house or shed, under woodpiles, beneath garbage cans, around garden beds, or tucked under dense ground-cover plants. The soil around an active entrance is often freshly disturbed, and you may notice a fan-shaped patch of kicked-out dirt in front of the hole.
Below the surface, rat tunnels run no deeper than about 18 inches and can extend roughly 3 feet in total length. A single burrow system usually has one main entrance plus one or two secondary escape holes that are less obvious, sometimes lightly covered with soil or debris. These bolt holes let rats flee quickly when threatened, so if you find one hole, look nearby for others.
Signs of activity beyond the holes themselves include greasy rub marks along walls or fences near the entrance, droppings (dark, capsule-shaped, about half an inch long), and worn pathways through grass or mulch. If you see rats during daylight, that’s a strong indicator of a large population, since they’re normally nocturnal and secretive.
Rat Holes vs. Other Animal Holes
Several yard-dwelling animals dig holes that can look similar at first glance, but the differences are straightforward once you know what to check.
- Chipmunk holes are about the size of a silver dollar (slightly smaller than rat holes) and tend to be very clean around the entrance with no pile of excavated dirt. Chipmunks are active during the day, so you’ll often see them near their holes.
- Vole holes are much smaller, roughly dime-sized, and usually appear around the roots of plants or at the base of trees. Voles also create visible surface runways through grass.
- Ground squirrel holes are similar in size to rat holes but noticeably clean on the outside. You’ll often find a second hole of similar size within about 20 feet, and ground squirrels are easy to spot on warm, sunny days.
- Mole activity looks completely different. Moles push up raised ridges of soil across the lawn and leave volcano-shaped mounds rather than clean round holes.
If the hole is 2 to 3 inches, smooth-edged, tucked against a structure or under cover, and you never see the animal using it during the day, it’s almost certainly a rat burrow.
Health Risks of Active Burrows
Rat burrows aren’t just a nuisance. Active colonies pose real health risks, primarily through contaminated soil and water. The most significant concern is leptospirosis, a bacterial disease spread through rat urine that seeps into surrounding soil and any standing water. A 2025 Tufts University study that analyzed over 300 rats in Boston found roughly 18% were carrying the bacteria responsible for the disease.
Most people who encounter the bacteria either fight off the infection without symptoms or develop a mild, short-lived fever. A small percentage, however, progress to serious illness that can affect the kidneys, liver, and other organs. The risk is highest when you have direct contact with contaminated soil or water, especially through cuts or broken skin. Dogs are also vulnerable, so yards with active burrows present a concern for pets that dig or drink from puddles.
Disturbing burrows through digging or construction can actually make things worse in the short term by forcing rats to scatter and spread contamination to new areas. That’s one reason it’s important to deal with the population before simply filling holes.
How to Get Rid of Active Rat Burrows
Filling an active burrow without addressing the rats themselves is pointless. They’ll dig new holes within days, sometimes overnight. The effective approach works in stages: reduce what’s attracting them, eliminate the population, then seal the burrows permanently.
Cut Off Food and Water
A rat needs only about one ounce of food and one ounce of water per day, so even small sources matter. Pick up fallen fruit from trees, clean up birdseed spills, secure trash in cans with tight-fitting lids, and put garbage out as close to pickup time as possible. Remove pet food bowls from outside overnight. Pick up dog waste promptly, as rats will feed on it. Sweep away standing water along curbs, in low spots, or in plant saucers.
Reduce Shelter Options
Rats prefer to burrow under cover where they feel protected. Clear clutter from along fences and foundations. Trim dense, low-growing bushes up off the ground and create visible space between plants. Move woodpiles, lumber, and stored materials away from the house. Rats need only 6 to 8 inches of soil depth to establish a burrow, so areas with loose, deep soil near structures are prime real estate for them.
Address the Population
Snap traps placed near burrow entrances are effective for smaller infestations. Position them perpendicular to walls with the trigger end against the base, since rats travel along edges. For larger infestations with multiple active burrow systems, professional pest control is often the practical choice. Some professionals now use a registered dry-ice product that releases carbon dioxide gas into burrows. This method is approved for outdoor use away from structures in states that have registered the product, but it’s not something homeowners can legally do on their own. The EPA restricts its use to licensed applicators using a specifically labeled product.
Seal Burrows Permanently
Once you’re confident the burrows are inactive (no fresh digging, no new droppings, entrance holes developing cobwebs or leaf litter), it’s time to fill them. Collapse the tunnels by pushing soil in firmly and tamping it down. For more durable results, fill holes with landscaping pebbles or gravel, which rats find much harder to re-excavate than loose soil. For gaps along foundations, sidewalks, or curbs, use a layered approach: stuff the opening with steel or copper mesh, seal over it with expanding foam, then cover with caulk or roofing cement. This layering prevents rats from chewing or pushing their way back through.
Cover bare soil in areas where burrows were active with a one-inch layer of fresh mulch or landscaping pebbles to discourage new digging.
Preventing New Burrows
Rats are opportunistic, so prevention is about making your yard a less appealing option than whatever’s next door. Keep vegetation trimmed so the ground beneath plants is visible. Maintain a clean perimeter along your home’s foundation with no soil mounded against the wall. Use heavy-duty trash bags to prevent rips and leaks that create food trails.
Seal any cracks or gaps in sidewalks, retaining walls, and the junction where concrete meets your foundation. These small openings serve as travel corridors that connect underground spaces and invite exploration. Regularly inspect the areas under sheds, decks, and porches, since these sheltered zones are among the first places rats choose to dig. If you have a raised deck, consider lining the perimeter underground with hardware cloth buried at least 12 inches deep to block burrowing access.
Check your yard every few weeks for fresh holes, especially in spring and fall when rat populations shift. A single new 2-to-3-inch hole along a foundation is easier to deal with immediately than a full colony you discover months later.