Something Is Digging a Huge Tunnel Under My Garden Shed — What Should I Do?

Signs of rabbits:

Smaller holes (2–3 inches wide)
Chewed vegetation nearby
Droppings that are small, round pellets
3. Rats or Mice
Rats and mice dig smaller tunnels and burrows along edges, but their holes are typically small and narrow. If what you’re seeing is large, it’s likely not rodents.

4. Skunks, Opossums, or Raccoons
These animals dig in search of insects, grubs, or worms. If the soil around your property is rich in food sources, you may see repeated digging around structures and gardens.

Signs of larger mammals:

Disturbed soil in broad patches
Scrape marks or footprints
Trash or food remnants nearby
5. Armadillos or Other Burrowing Species
In some regions, armadillos, badgers, or other digging mammals create deep burrows. These tunnels can be extensive and destructive if left unchecked.

Why Filling the Tunnel Doesn’t Work
Filling the tunnel with dirt or gravel might seem like a logical step, but in most cases, it doesn’t stop the digging. Here’s why:

Animals See Filling as a Challenge
Many burrowing animals will simply dig around fresh fill. They see the disturbance as something new to explore or clear and will continue tunneling.

Loose Soil Is Easy to Move
When soil is loose or freshly dumped, it’s actually easier for a digging animal to push aside. Solid, tightly packed soil with barriers is much more difficult to bypass.

The Source Isn’t Just the Hole
The problem isn’t just the opening — it’s the reason the animal is there in the first place. Whether it’s food, shelter, or instinct, the animal has motivation to stay and dig.

Steps to Stop the Tunnel and Protect Your Shed
Here’s a comprehensive plan you can follow to tackle the problem effectively and prevent further structural damage:

1. Identify the Animal
Before you can stop the digging, try to determine what is digging. Look for tracks, droppings, or behaviors around sunrise and sunset when many animals are most active.

Large holes + soil mounds: Likely groundhogs or badgers
Small repetitive holes near edges: Possibly rabbits or rodents
Shallow scrapes and scattered digs: Larger mammals searching for food
2. Install a Barrier Around the Perimeter
Animals will stop digging if they encounter a physical barrier that is difficult to penetrate. Consider one or more of these:

Wire mesh or hardware cloth: Bury it 1–2 feet into the ground perpendicular to the shed foundation
Concrete or cement collars: Pour a reinforced footing around the base to block underground access
Large stone or gravel apron: This can discourage digging if it extends out from the slab
A barrier needs to be buried deep enough that the animal cannot simply dig under it.