What should you do about groundhogs under a shed?

You walk out to grab a rake from the backyard shed and notice a tidy mound of fresh subsoil piled up right against the wooden baseboards. A heavy, roly-poly creature with brownish-gray fur scrambles under the rim joist, and suddenly you realize you are sharing your property with a groundhog. It is easy to see why they pick these spots. A shed offers a readymade roof, absolute shelter from rain and hawks, and far less digging effort than carving out a brand-new den in an open pasture.

You might think the simplest fix is to rent a trap, haul the animal off to a distant state park, and call it a day. Unfortunately, treating this like a simple guest eviction rarely works. If you catch and remove a groundhog without blocking the opening, you have just left a luxury hotel room vacant in a busy neighborhood. Another animal from down the street will move into the empty burrow almost immediately.

What you actually need to do is permanently exclude them by sealing the space with heavy wire mesh. But you cannot just roll out wire and slap it against the walls tomorrow morning. If you seal the structure while an animal is still tucked away inside, or worse, while a mother is nursing helpless babies beneath the floorboards during spring, you create a major humane problem and a terrible odor.

Before you start digging or buying materials, you have to confirm what is actually living under your floorboards. Groundhogs are not the only creatures that enjoy burrowing under outbuildings, and guessing wrong wastes your time. Look closely at the tracks in the mud or soft soil around the entrance. Groundhogs usually leave four-toed prints with prominent claw marks on their front feet and five-toed tracks on their hind feet.

You should also measure the main entrance hole. A typical groundhog den opening usually spans about 10 to 12 inches across, accompanied by that characteristic mound of excavated dirt. Skunks and raccoons might squeeze under a shed, but they rarely move that volume of subsoil.

Once you find the holes, you have to run a simple vacancy test before doing any construction. Take some crumpled newspaper or a few lightweight sticks and wedge them loosely into every entrance and exit hole you can find. Leave those obstacles alone for at least 3 consecutive days of clear, dry weather. If you come back and the paper is shoved out or the sticks are knocked aside, your tenant is still active and using that door. If the paper sits completely untouched for three full days of good weather, the burrow is temporarily vacant. Do not skip this step, and remember that winter hibernation will give you a false sense of an empty burrow because the animal is simply sleeping deeply inside.

Once you have confirmed the burrow is empty during the active spring-to-autumn months, you can install a proper physical barrier. Forget about ultrasonic noise gadgets, plastic visual owls, or mothballs tossed under the floor. Groundhogs quickly get used to strange smells and sounds when good shelter is on the line, and those quick fixes have very little scientific backing.

Instead, you need to build a mechanical exclusion system using heavy galvanized wire mesh, often called hardware cloth. The secret to making this work is an underground L-footer design. Think of it like laying down a heavy rug half under a door. When an animal tries to scratch at the base of the wall, its paws hit the flat wire on the ground first, stopping it from digging straight down.

Start by digging a trench 1 to 2 feet deep all the way around the perimeter of the shed. Fasten your heavy wire mesh securely to the bottom wall plate or rim joist of the shed using heavy staples or screws. Drop the mesh down into your trench, and then bend the bottom 1 foot of wire outward at a 90-degree angle so it extends away from the structure underground. Backfill the trench with soil or crushed stone and tamp it down firmly. When a groundhog tries to dig back under the wall later, its claws hit that horizontal underground shelf of wire, and it will give up and move elsewhere.

There are times when a DIY weekend project is simply not the right call. If you peek under your shed during the spring or early summer and suspect a mother groundhog has birthed a litter of dependent young down there, step back. Sealing the burrow traps immobile babies inside, which leads to severe humane issues and intense decomposition odors beneath your floor.

You should also call in a licensed wildlife control operator if the burrow sits beneath a sagging concrete slab or an unstable structure where digging could cause a sudden cave-in. Wild mammals can carry rabies and other diseases, and any direct bite or scratch requires immediate medical attention from a clinician or your local public health authority. If local laws restrict handling or if structural repairs require heavy shoring and concrete work, let a professional handle the heavy lifting.