What Should I Put In Chipmunk Holes? | Yard-Safe Fixes

Chipmunk tunnels can leave soft spots, undermine steps, and invite more digging. The fix starts with picking the right filler, using it at the right time, and avoiding banned or risky products. This guide shows what to put in chipmunk holes, how to place it, and how to keep new holes from popping up.

The goal isn’t to hurt animals. The goal is to close gaps, protect foundations, and steer chipmunks to safer spots. You’ll see simple materials that work, plus clear no-go items backed by agency rules and extension tips.

What To Put In A Chipmunk Hole Safely

Start by checking that no pups are underground. Spring litters are common, with a second round in late summer in some regions. If you hear squeaks or see small chipmunks near the entrance, wait a few weeks.

Once the burrow is empty, fill in layers. Use soil or pea gravel first, then a tight cap of 1/4-inch hardware cloth trimmed a few inches wider than the hole. Add more soil on top and tamp. Water lightly, let it settle, and top off as needed.

That cap stops quick re-digging while allowing water to drain. Soil alone can work in lawns, but the mesh layer holds longer near patios, walks, sheds, and retaining walls.

Step-By-Step Fill Method

1. Scoop loose soil back into the run. Add pea gravel if the tunnel keeps swallowing fill.
2. Cut a square of 1/4-inch hardware cloth that extends 2–4 inches past the entrance on all sides.
3. Lay the mesh flat over the plug. Pin with landscape staples if the surface is soft.
4. Backfill with soil to cover the mesh by at least two inches. Tamp with your boot or a hand tamper.
5. Water to settle. Refill flush with grade. Seed or mulch to match the site.

Mark the spot on a simple sketch or phone photo. If you see a fresh opening nearby, repeat the steps. Many burrow systems have more than one exit.

Quick Tip On Tamping

Use a short scrap 2×4 as a flat tamper where space is tight. Light taps firm the plug without crushing roots.

When Not To Fill Yet

Skip filling if the ground heaves after heavy rain. Let water drain, then repair. Skip filling when a burrow runs under steps or slabs that feel unstable. Fix supports first, then plug openings.

If you still see active traffic in and out, use a one-way door on the hole for three to five days. Once movement stops, remove the door and close the opening the same day.

Soil Or Gravel — Which Holds Better?

Soil blends in, grows grass, and looks natural right away. It compacts well after a light soak and a tamp. Pea gravel resists tunneling near hard edges where paws get extra leverage. Many yards use both: soil for the main plug and a thin gravel layer below the mesh to stiffen the patch.

Skip concrete in holes. Wet mix can flow into unseen runs and trap wildlife. If a slab needs support, a pro can lift it and add base rock from the side. Then you can plug the small surface openings with the method here.

Mesh Size And Metal Choice

Pick 1/4-inch hardware cloth, not window screen. The grid is small enough to block digging and strong enough to resist chewing. Galvanized steel holds up under mulch and wet soil. Where rust is a worry, use stainless mesh for the top layer and save galvanized for deeper footers.

Trim sharp edges with tin snips and fold corners under. Gloves help. A tidy square is easy to bury and won’t snag roots or feet later.

Seasonal Timing That Works

Most yards run smoother when heavy repairs land in late summer or fall. Young are above ground, soil is workable, and plants bounce back fast. Spring can work too; just give any new litters time to move out. Winter soil is often frozen or water-logged, so plugs fail.

If a storm opens a hole, don’t wait months.

Putting Filler Into Chipmunk Holes Near Foundations

Holes along foundations deserve extra care. Lift mulch, brush away loose soil, and check for cracks or openings. Close gaps in siding or vents with 1/4-inch hardware cloth and sealant. Then fix the hole at grade.

After the basic plug and mesh cap, add a narrow trench of crushed stone along the wall, five to eight inches deep and six to eight inches wide. That stone border, often called a plant-free gravel strip, makes fresh digging tough and sheds splashback from rain.

For spots that chipmunks keep testing, build an L-shaped footer from 1/4-inch hardware cloth. Lay it flat under the topsoil with the short leg turned outward from the wall. The mesh sits two to four inches below grade and extends out a foot. This layout blocks tunneling right at the edge without visible fencing.

Hardware Cloth Footer Setup

1. Cut a strip of 1/4-inch mesh 18–24 inches wide. Bend a 4–6 inch lip to form the L.
2. Dig a shallow trench along the wall. Set the short leg down and the long leg outward.
3. Stake the mesh. Backfill with soil and, if desired, a layer of pea gravel on top, then mulch.

This same layout works along steps, AC pads, and retaining walls.

What Not To Put In Chipmunk Holes

Avoid mothballs, flakes, or crystals. Labels limit use to sealed containers for fabric pests. Outdoor use or use in open holes breaks the label and can harm kids, pets, and wildlife.

Don’t pour bleach, ammonia, or gasoline into burrows. Fumes can collect under floors or near pilot lights. Liquids can move through soil and damage roots or wells. Repellent powders and spices seldom last and can foul soil where you want plants.

Skip makeshift fumigation with dry ice or charcoal. Some burrow fumigants are federal-restricted products for trained applicators only. Home use without training and permits is unsafe and can carry fines.

Humane Ways To Empty Burrows First

Close food sources so the burrow quiets down. Clean fallen seed under feeders, switch to seed that leaves less waste, and hang trays to catch shells. Move rock piles and stacked lumber that give cover.

Build a small one-way door from a wire cage panel. Hinge the top, set it over the entrance, and weight the edges so the flap lifts only outward. Check twice a day. When activity stops, remove the door and fill.

Plant choices help near old runs. Daffodils and allium are less attractive than tulips. For bulbs, lay 1/4-inch hardware cloth over the bed before covering with soil. Plants grow through the mesh while the barrier blocks digging right above the run.

Garden Beds And Bulbs Near Old Runs

Fresh runs through beds can make a mess of bulbs and seedlings. Mesh saves you from replanting again and again. Lay 1/4-inch hardware cloth over the bed after planting, pin it, then cover with two to three inches of soil. Shoots pass through the grid while the barrier blocks quick digs.

Chipmunks love easy calories. Tulips and crocus often vanish. Daffodils and allium stick around more often. A bulb cage around small clumps also helps. Fill holes from old runs, cap with mesh, then add your planting mix.

Along the bed edge, a six-inch strip of crushed stone over a buried mesh lip keeps the line tidy and tough. Weed fabric on top is optional; soil and mulch on top finish the look.

Pets, Kids, And Safety While You Work

Wear gloves and eye protection when cutting mesh. Keep pets indoors during the fill so nobody noses into a half-filled run. Store any repellents far from reach and read labels start to finish. Most yards need no chemicals when you pair soil, stone, and mesh.

If you use a one-way door, set a calendar reminder to remove it. Leaving devices in place can trap debris and confuse pets. Once the door is off, fill that day and water the patch.

Long-Term Fixes So Holes Don’t Return

• Keep a six- to eight-inch gravel edge along slabs and steps.
• Edge beds with stone set over a buried strip of 1/4-inch mesh.
• Store pet food and seed in tight bins; feed birds in short bursts, then pause.
• Where digging threatens slabs, add a hidden L-shaped footer during any yard refresh.
• Fix downspouts and grade so water flows away; soggy soil caves in and opens runs.

Near walls, foundations, and stoops, a little steel and stone go a long way. That mix lets you avoid harsh products and repeat damage.

Troubleshooting: If A Hole Reopens

Fresh soil around yesterday’s plug points to a second exit. Walk a slow circle five to ten feet out and look for a small, tidy opening with no mound. Plug that one first, then return to the original hole and finish the steps.

If the cap holds for a week, seed the patch or tuck in a small groundcover. Roots tie the top layer together and make re-entry tougher.

When tunnels track under slabs or walls and you see cracking or sinking, call a local contractor or wildlife pro. The fix may involve foam jacking, new base material, or a trench footer paired with mesh. After that work, close any visible holes with the method above.

Quick Shopping List

• Two to three sheets of 1/4-inch hardware cloth (rolled or flat panels)
• Tin snips and gloves
• Landscape staples and a hand tamper
• Two bags of pea gravel and a bag of topsoil
• Crushed stone for borders near walls and steps
• Seed, mulch, or a low groundcover to finish the patch

Most home centers stock these items year-round. One afternoon of work can close a lot of openings when you prep tools first.

How This Advice Stays Safe And Legal

The products listed here favor building materials over poisons. That matches guidance from wildlife groups and university extensions. Outdoor mothball use breaks label rules and risks harm. Fumigants for burrows fall under tight rules for a reason. When in doubt, pick soil, gravel, and mesh, or hire a licensed operator.

For more detail on chipmunk burrows and damage risks, see this Purdue Extension note. For safe repellents and barriers near homes and gardens, see the Humane Society’s tips on working with chipmunks. For rules on pesticide products such as mothballs, check the NPIC guidance.

A calm, stepwise repair beats harsh tricks. Fill with soil and stone, back it with mesh, and tidy food sources. Your yard stays solid, the burrow shuts down, and the fix lasts. Work steadily now.