Groundhog vs. mole holes: how to tell the difference

Updated 2026-02-02

Direct answer

Groundhog damage usually means a big open entrance (often ~10–12 inches across) with a dirt pile nearby—often close to structures. Mole damage usually looks like raised surface ridges and “volcano” mounds from tunneling, not a large open hole you can see into. If the holes are small and clean with grass runways, also consider voles.

Quick decision table

What you see	Most likely	Do this next
Large open hole (roughly a foot wide) + excavated dirt pile; often near shed/deck/foundation	Groundhog	Confirm activity, then removal/exclusion; don’t seal while active
Raised ridges/snaking lines in lawn; soil “pushed up” but no big entrance	Moles	Identify active runs, reduce activity, then repair turf
Volcano-shaped mounds of soil popping up across yard	Moles	Flatten mounds, locate active paths, focus control there
Small clean holes + narrow runways in grass; plant chewing/girdling	Voles (often, not moles)	Reduce cover, protect plants, consider trapping strategies for voles

Spot-the-difference checklist

Clue	Groundhog burrow	Mole activity
Entrance size	Large, obvious opening (often ~10–12 inches wide)	Usually no big open entrance; tunnels are below surface
Soil pattern	Piled excavated dirt near the opening; can look like a mound beside the hole	Volcano mounds or fan-shaped mounds; lots of small piles across yard
Surface signs	Paths to garden; chewed plants; multiple entrances possible	Raised ridges (surface runways) that feel squishy when stepped on
Location	Often near sheds, decks, porches, slabs, tree lines, foundations	Anywhere in turf/gardens; patterns may crisscross large areas
Risk level	Trip hazard + possible undermining near structures	Mostly turf damage; plants may loosen from root disturbance

How to confirm in 10 minutes

Measure the opening: If it’s “softball-to-basketball” sized (huge), treat it like a groundhog burrow.
Look for surface ridges: Long raised lines in the lawn strongly point to moles.
Check the soil “style”: One big entrance with a dirt pile next to it suggests groundhog; scattered volcano mounds suggest moles.
Do a 24-hour activity test (groundhog): Smooth the dirt at the entrance and see if fresh digging appears the next day.
Prioritize safety near structures: If the suspected burrow is under a deck/shed/steps or right by a foundation, treat it as higher risk and consider a pro sooner.

What to do next

If it’s a groundhog burrow: Don’t seal it immediately. Confirm activity → remove/exclude → then backfill and compact. Long-term prevention is buried mesh and fence “dig-under” protection (buried edge or outward “L” footer).
If it’s moles: Think “tunnel system,” not “one hole.” Focus on identifying active runs, reducing activity, and repairing turf. Moles primarily chase insects underground, so you’re usually solving a turf/tunnel problem, not a den under a shed.
If it might be voles: Reduce cover (tall grass, mulch right up to stems), protect trunks/plants, and use vole-specific control methods.

Common mistakes

Assuming any hole means moles: moles often leave ridges/mounds, not a big open entrance.
Filling a large burrow right away: sealing a groundhog inside can create odor and new escape digging.
Ignoring location: a large hole beside a slab, steps, or shed is a higher priority than random turf mounds.
Chasing every mole mound: pick the most active areas instead of fighting the whole yard at once.
Missing “vole signs”: small holes + runways + plant chewing is often voles, not moles.

FAQ

What size is a groundhog hole?

Groundhog (woodchuck) burrow entrances are typically large and obvious—often around 10–12 inches in diameter, with excavated soil nearby. If you can comfortably fit your foot into it, treat it like a groundhog-style burrow.

Why do I see ridges in my lawn but no big hole?

That pattern is classic for moles. Their shallow tunnels can create raised, squishy ridges across turf. You may also see volcano-like mounds where soil was pushed up from deeper runs.

Could this be voles instead of moles?

Yes. Voles often leave small clean openings and visible runways in grass and can chew plants and bark. Moles mostly cause tunneling and mounds while hunting insects underground.

If the hole is under my shed, is it more likely groundhog?

Often, yes. Groundhogs commonly dig dens under sheds, porches, slabs, and along foundations. Treat these as higher priority because confirming exits and preventing re-entry usually requires exclusion mesh and careful timing.

Should I fill tunnels and holes the same way for both?

No. For a large burrow entrance, don’t fill until you’re sure it’s inactive or the animal is out/removed—then backfill and compact. For mole ridges/mounds, filling is cosmetic and temporary; the goal is reducing activity and then repairing turf.

Groundhog vs. mole holes: how to tell the difference
Use hole size, soil patterns, and surface tunnels to quickly identify whether you’re dealing with a groundhog burrow or mole activity—plus what to do next.
How to tell if a groundhog burrow is active
Learn the simplest signs a groundhog burrow is currently in use, how to check safely, and when it’s safe to fill and exclude the hole.
Can groundhog burrows cause foundation damage?
Groundhog burrows can contribute to foundation issues by undermining soil, worsening drainage, and creating voids near slabs. Here��s what to watch for and what to do.
Do mothballs, ammonia, or ultrasonic repellents work for groundhogs?
Do mothballs, ammonia, and ultrasonic devices actually work for groundhogs? Learn why these repellents usually fail, what can be risky, and what works instead (exclusion + proper backfill).
Groundhog burrow entrances: how many there are and how to find them
Groundhog burrows often have multiple hidden entrances. Learn how many holes to expect, where escape exits are usually located, and how to find them before sealing.

Sources and assumptions

Groundhog burrow ID: large entrance openings and excavated soil near entrances; commonly near structures/edges.
Mole ID: raised surface ridges and volcano-like soil mounds from shallow/deep tunnel systems.
Small “clean” holes and runways can indicate voles; confirm before applying the wrong solution.
This page is informational and not a substitute for local legal guidance on wildlife handling.