Chipmunks are the cartoon characters of the wildlife world. With their chubby cheeks and racing stripes, they are undeniably cute. Many Louisville homeowners tolerate them or even feed them peanuts on the back porch.

But beneath that adorable exterior lies a relentless excavator. A single Eastern Chipmunk can create a burrow system up to 30 feet long with multiple entrances, nesting chambers, and food storage tunnels.

When they choose to dig these tunnels next to your home, they can cause problems that are far from cute.

The Structural Risk: Fact vs. Fiction

The Myth: “Chipmunks will make my house collapse.” The Reality: It is extremely rare for chipmunks to cause a catastrophic structural failure of a main house foundation. Your house is heavy, and the footings are deep. A few chipmunk tunnels won’t topple it.

The Real Danger: While they won’t knock your house down, they frequently cause damage to lighter structures:

• Concrete Slabs: Patios, sidewalks, and driveways are often poured over a layer of gravel or dirt. Chipmunks love to dig out this substrate. Without support, the concrete slab can crack, settle, or tilt.
• Retaining Walls: They burrow behind stone or timber walls, causing them to lean or collapse over time.
• Stairs: Concrete or brick steps can pull away from the house as the ground beneath them is hollowed out.

The Water Problem

The biggest threat chipmunks pose to your home is water damage.

When a chipmunk digs a tunnel next to your foundation, they destroy the compacted soil that is supposed to slope away from your house.

1. The Funnel Effect: The burrow acts like a pipe. When it rains, water runs into the hole and is channeled directly down to your foundation wall.
2. Hydrostatic Pressure: This water accumulation increases pressure against your basement walls, leading to cracks and leaks.
3. Erosion: Over time, the water flowing through the tunnels washes away more soil, creating larger voids.

Signs of a Problem

Chipmunk burrows are neat, round holes about 2 inches in diameter. Unlike groundhogs, chipmunks carry the dirt away in their cheek pouches, so you usually won’t see a mound of dirt next to the hole.

Look for these holes:

• Along the foundation wall.
• Under the edge of patios or sidewalks.
• Near downspouts (they use the splash blocks for cover).
• In planter boxes or retaining walls.

How to Control Them

1. Habitat Modification (The “Un-Welcome” Mat) Chipmunks need cover to travel safely.

• Move wood piles and rock stacks away from the house.
• Trim bushes so they don’t touch the ground, removing their hiding spots.
• Stop Feeding Them: If you have bird feeders, you have chipmunks. Clean up spilled seed daily or move feeders at least 20 feet from the house.

2. Exclusion

• Seal Gaps: Use caulk or concrete to seal gaps between your patio/steps and the foundation.
• L-Footer: For garden walls or sheds, bury 1/4 inch hardware cloth in an L-shape to prevent digging.

3. Trapping If the population is out of control, trapping is necessary.

• Rat Snap Traps: Large wooden snap traps (the kind used for rats, not mice) are effective. Place them perpendicular to the wall near burrow entrances. Cover them with a box (with a small hole cut in it) to protect birds and pets.
• Live Traps: Small cage traps baited with peanut butter and sunflower seeds work well, but remember that relocating animals is often illegal or stressful for the animal.

If you are worried about your foundation or tired of tripping over holes in your walkway, Critter Removal of Louisville can help assess the damage and implement a control plan.