Is it legal to remove groundhogs myself in New Hampshire?

Yes — groundhogs (woodchucks) are unprotected in New Hampshire and can be legally trapped and relocated or dispatched year-round without a permit by the property owner. However, NH Fish & Game recommends licensed Wildlife Control Operators for colony removals or for situations where burrows are adjacent to building foundations. The NH WCO directory is at wildlife.nh.gov. Practical note: relocating a trapped groundhog without fixing the burrow opening means a new animal takes over within weeks. Pair any trapping with permanent exclusion fencing for lasting results.

Will a groundhog undermine my house foundation?

It can — and the risk is real enough to take seriously. A single groundhog burrow system averages 50–100 feet of tunnels and displaces roughly 275 pounds of soil at the main entrance alone. Burrows placed directly under or adjacent to frost walls, deck footings, or shed pads remove the bearing material that keeps those structures level. The damage worsens over multiple seasons and accelerates with each freeze-thaw cycle — NH winters are hard on already-undermined footings. If you see a burrow entrance within 3 feet of any structure's foundation, treat it as a priority and have the burrow mapped and excluded promptly.

How do I tell a groundhog burrow from a chipmunk hole?

The size and the mound are the fastest tells. A groundhog main entrance is 10–12 inches in diameter — big enough to put both fists in side by side — with a prominent fan-shaped mound of excavated soil pushed outward. A chipmunk hole is about 2 inches across with no mound at all (chipmunks carry dirt away in cheek pouches). A Norway rat hole is 2–3 inches across with a smaller, less organized soil pile. If the hole looks like a small shovel excavated it and left a dirt pile at the edge, it's a groundhog.

What is a plunge hole?

A plunge hole — also called a secondary entrance or spy hole — is a moundless emergency escape entrance that the groundhog digs from inside the burrow outward. Because there is no excavated soil pushed to the surface, plunge holes are nearly invisible at ground level, especially when hidden in tall grass or dense vegetation. They are typically 4–6 inches in diameter. Plunge holes are the key unknown in any groundhog exclusion project: filling or fencing only the main entrance while missing two or three hidden plunge holes guarantees the groundhog will re-enter. A thorough burrow inspection must locate all entrances before exclusion can succeed.

When do groundhogs have babies?

Groundhogs have one litter per year. Mating occurs shortly after the animals emerge from hibernation — February to March in southern New Hampshire. After a gestation of approximately 32 days, 2–6 young (average 4–5) are born in April or May. The young remain in the burrow for 5–6 weeks before beginning to venture out. By July or August, the young of the year have dispersed and are establishing their own burrow systems — which is why homeowners often discover new burrows under outbuildings in midsummer. Exclusion or removal during April and May risks trapping dependent young underground.

Does filling the burrow work?

Not as a standalone fix, and not for long. A groundhog that returns to a filled main entrance will re-excavate it within a day or two — the animal simply digs back through the loose fill. Filling is only useful as a monitoring tool: pack the entrance tightly with soil, check it in 24–48 hours, and if the fill is disturbed, you know the burrow is still occupied. The lasting solution is physical exclusion — galvanized hardware cloth buried 10–12 inches deep with an outward L-bend that the animal cannot dig around or under. Exclusion fencing paired with removal of the resident animal is the only approach with a durable outcome.

What time of year should I do groundhog exclusion?

Late summer to early fall — roughly late July through September — is the optimal exclusion window in New Hampshire. By late July, the young of the year have dispersed from the birth burrow, eliminating the risk of trapping pups underground. The resident adult is still active and can be confirmed out before the entrance is sealed. Exclusion in this window also gives the new fencing a full winter to settle before groundhog activity resumes in spring. Avoid exclusion in April and May (dependent young present) and mid-November through February (animal may already be in hibernation in the burrow).

Are groundhogs dangerous to people?

Groundhogs are not aggressive under normal circumstances and will retreat to the burrow when approached. The primary physical hazard they pose is structural — undermined footings, hidden plunge holes — rather than direct confrontation. Bites are rare and typically occur when the animal is cornered or handled. However, groundhogs are a documented (if low-probability) rabies vector, and any unprovoked bite or unusual daytime aggression from a groundhog should be reported immediately to NH DHHS Bureau of Infectious Disease Control at (603) 271-4496. Do not handle a groundhog that appears disoriented or aggressive.

Will a groundhog come back after I remove it?

The individual animal you remove will not return if relocated far enough (5+ miles is the standard professional recommendation). However, an unexcluded burrow system is prime real estate: it offers ready-made tunnels, proven drainage, and established cover. A new groundhog — often a dispersing juvenile from a nearby litter — typically occupies an open burrow within days to weeks. This is why trapping alone without exclusion fencing is a treadmill for homeowners. Remove the animal and install permanent exclusion at the same time for a result that holds.

How much does groundhog removal cost in New Hampshire?

Cost depends on the number of burrow entrances, the proximity to structures, and whether exclusion fencing installation is included in the same visit. Anchor Pest Services provides free, no-obligation quotes and same-day service across southern New Hampshire. Because each burrow situation is different — a single open-field burrow versus one tunneling under a concrete deck footing require different approaches — we do not publish flat rates. Contact us for a site-specific assessment.

Groundhog · Marmota monax

WildlifeNH resident

Groundhogs in New Hampshire — Burrows, Damage & Control

Also called Woodchuck · Whistle-pig · Land beaver

The groundhog (Marmota monax) — also called woodchuck or whistle-pig — is New Hampshire's most destructive burrowing mammal. A single burrow system can span 50–100 feet underground and displace 275 pounds of soil, undermining shed floors, deck footings, walkways, and foundation walls. Groundhogs are true hibernators (active April–October) and are found statewide in NH. Exclusion fencing buried with an outward L-bend is the most reliable long-term fix; simply filling the burrow does not work.

At a glance

Weight: 5–12+ lb; Heaviest before hibernation; Penn State Extension
Body size: 16–20 in head-body; tail 4–7 in; Marmota monax adult; Penn State / Mass Audubon
Burrow length: 50–100 ft (15–30 m); Rarely exceeds 6 ft deep; ESF / Carnegie Museum of Natural History
Soil displaced: ~275 lb per main entrance mound; Carnegie Museum of Natural History study average
Hibernation: True hibernator: Oct/Nov–Feb/Mar; Unlike gray squirrels, which remain active all winter
Litter: 1 litter/yr of 2–6 young; born April–May; ~32-day gestation; Penn State Extension / Mass Audubon
NH range: Found throughout all of New Hampshire; Monadnock Pest / NH context

The short of it

The burrowing mammal that undermines NH foundations and decks

The groundhog (Marmota monax) — widely called a woodchuck in New Hampshire, and occasionally a whistle-pig for its alarm call — is the largest member of the squirrel family in the northeastern United States. It is a dedicated burrower: a single adult maintains a tunnel network that can extend 50 to 100 feet underground with two to five entrances, and the main entrance mound alone represents roughly 275 pounds of excavated material.

That excavation is the core problem for homeowners. Groundhog burrows routinely tunnel under deck footings, shed pads, concrete walkways, staircase foundations, and in severe cases, the frost walls of residential structures. Undermined footings settle unevenly; tunnel collapse injures livestock and can damage riding mowers and ATVs. NH Fish & Game notes the species is found throughout the entire state, from the Seacoast up through the North Country.

Groundhogs are true hibernators — they enter torpor by late October or November and re-emerge in late February or March, making them a warm-season pest from roughly April through October. One litter of 2–6 young is born in April or May, and the young disperse by midsummer, which is when homeowners typically discover new secondary burrows appearing under outbuildings. The good news: New Hampshire has no closed season on groundhogs, and a well-installed exclusion fence is a permanent fix.

Identify it

How to identify a groundhog and its burrow

The groundhog is a stocky, short-legged mammal with a coarse gray-brown coat, a relatively flat head, and a short bushy tail. The burrow is often the most visible sign: look for a 10–12-inch entrance hole with a prominent fan-shaped mound of excavated soil pushed to one side.

Species profile

Groundhog

Scientific name: Marmota monax
Family: Sciuridae
Size: 16–20 in head-body; tail 4–7 in; weight 5–12+ lb (heaviest just before hibernation)
Coloration: Coarse, grizzled gray-brown above; yellowish-brown on the underside; dark feet; short, dark bushy tail
Habitat: Open fields, meadow edges, forest margins, roadsides, and suburban yards with open ground; dens under sheds, decks, porches, stone walls, and fencerows
Active season: April–October (true hibernator; enters torpor Oct/Nov, re-emerges Feb/Mar in NH)
Diet: Grasses, clover, alfalfa, garden vegetables, fruits, and bark of young trees and shrubs
Reproduction: One litter per year; 2–6 young (average 4–5) born April–May after a ~32-day gestation; young disperse July–August
Lifespan: 2–6 years in the wild

Found throughout all of New Hampshire; common in agricultural fields, roadsides, suburban yards, and under human structures statewide.

The tells — key ID features

Stocky, low-slung body with short legs — moves with a waddling gait and is a surprisingly fast runner when alarmed.
Coarse grizzled gray-brown coat; short, flat-topped head with small rounded ears set close together; no mask and no stripes.
10–12-inch burrow entrance with a conspicuous fan-shaped mound of excavated soil pushed to one side at the main entrance — the single most reliable field sign.
Hidden 'plunge-hole' secondary entrances — moundless, often concealed in tall grass or brush — that are the key unknown making burrows hard to locate and seal.
Well-worn, flattened trails connecting burrow entrances to feeding areas, often visible across lawns or through garden beds.
Gnawed lower bark on young fruit trees and shrubs; clean diagonal cuts on garden plant stems at ground level.

Size, to scale

The insect

16–20 in body; 5–12+ lb

Compared to

About the size of a large house cat, but stockier and lower to the ground

Looks bigger than it is

Groundhogs entering hibernation can weigh 12+ pounds — significantly heavier than they appear in spring. The burrow entrance diameter (10–12 in) is the most useful size reference in the field.

Is it actually this? — the confusion species

Beaver

How to tell — Much larger (30–60 lb), aquatic, with a broad paddle-shaped tail. Beavers are always near water; groundhogs are never in it by habit.

Muskrat

How to tell — Smaller than a groundhog (1–4 lb), semi-aquatic, with a scaly, laterally flattened tail. Found in wetland margins, not under suburban decks.

Large raccoon

How to tell — Raccoons have a distinctive black face mask and ringed tail; groundhogs have neither. Raccoons den in hollow trees or under structures but do not produce the fan-shaped burrow mound.

What you'll notice

Signs of a problem

Groundhog evidence centers on the burrow itself and the feeding damage radiating out from it. Knowing the difference between a main entrance and a plunge hole is essential for finding the full burrow system.

10–12-inch entrance hole with a fan-shaped mound of excavated soil pushed to one side

What it means — The main entrance signature — contrasts with chipmunk holes (2 in, no mound) and Norway rat holes (2–3 in, smaller mound). The fan shape is caused by the groundhog pushing soil outward while digging.

Moundless 2–4-inch secondary holes nearby, often hidden in vegetation

What it means — These are 'plunge holes' — emergency escape entrances with no mound because the groundhog digs them from inside out. Easy to miss and dangerous to livestock, equipment, and people.

Well-worn, flattened grass trails leading from the burrow to feeding areas

What it means — Groundhogs use fixed routes to and from gardens and open feeding areas; trails become visible after a few weeks of regular use.

Garden crops grazed at ground level with clean angled cuts on stems

What it means — Groundhogs clip plant stems and leaves cleanly; damage appears suddenly because they graze heavily in morning and early evening.

Gnawed or stripped bark on the lower 6–12 inches of young fruit trees or shrubs

What it means — Groundhogs gnaw bark to wear down incisors and for moisture during dry periods; repeated damage can girdle and kill young trees.

Soil settling, cracking, or void under a deck, shed pad, or walkway

What it means — Direct evidence of undermining — the tunnel has removed the support material beneath the structure. Inspect promptly; foundation damage worsens with each freeze-thaw cycle.

How much it matters

The real risks, calibrated

Groundhogs are not aggressive under normal circumstances, but the structural and safety consequences of active burrows under or near buildings can be substantial.

Overall risk

Moderate

Undermining of foundations, sheds, decks, and walkways

High

Onset: Progressive over weeks to months

Burrow excavation removes support material from beneath footings and pads. Structures settle unevenly; concrete walkways and stairs crack; in severe cases, frost walls shift. One study averaged 275 lb of excavated soil per main entrance — enough to create a significant void under a small shed pad.

Burrow hazard to people, equipment, and livestock

Moderate

Onset: Present from the time hidden plunge holes are established

Moundless plunge holes are invisible in tall grass and easily stepped into, causing ankle or leg injuries to people and livestock. Riding mowers, ATVs, and tractors can drop a wheel into a hidden burrow collapse.

Garden and agricultural crop loss

Moderate

Onset: From first emergence in spring; peaks May–August

A single groundhog can devastate a backyard vegetable garden within days. Groundhogs graze heavily and systematically, targeting legumes, brassicas, and leafy greens first.

Rabies — rare but reportable in NH

Low risk

Onset: On direct contact or bite

Groundhogs are a low-probability rabies vector, but woodchuck bites or unusual daytime aggression warrant immediate contact with NH DHHS Bureau of Infectious Disease Control: (603) 271-4496. Do not handle an aggressive groundhog.

What you can do

DIY — what works, what backfires

Groundhog control is primarily an exclusion problem, not a trapping problem. A trapped and relocated groundhog leaves a burrow system that another animal — or another groundhog — occupies within weeks. These are the methods that actually work.

What actually works

Install exclusion fencing: galvanized hardware cloth or welded wire (2x2-inch mesh), at least 3–4 feet above ground and buried 10–12 inches deep with an outward-facing L-bend (6–8 inches) at the bottom to defeat digging. The above-ground portion should bow outward at the top rather than be rigid — groundhogs are good climbers.
Bury L-bend mesh along shed foundations and deck perimeters where burrowing is active, extending 6 inches outward underground before turning down.
Time evictions for late summer or early fall — after the young have dispersed from the burrow (July–August) and before groundhogs enter hibernation (October). This avoids trapping dependent young underground.
Use a licensed Wildlife Control Operator for trapping where exclusion must be paired with live removal of the resident animal.

What backfires

Don't fill the burrow with rocks, soil, or concrete alone — a groundhog returns to a filled burrow and re-excavates it within days; only properly installed exclusion fencing prevents re-entry.
Don't attempt exclusion in April–May when young may be present in the burrow — trapped pups cannot emerge and will die underground.
Don't exclude during hibernation (November–February) without confirming the groundhog has not yet entered torpor; a sealed groundhog in the burrow will die there.
Don't rely on commercial repellents, predator urine, or ultrasonic devices — no peer-reviewed evidence supports any of these for groundhog control, and field results are consistently negative.

Local Context

Groundhogs in New Hampshire — statewide and under your shed

Groundhogs are found throughout all of New Hampshire — from the coastal towns of the Seacoast to the Connecticut River valley and into the White Mountains foothills. In Anchor Pest's southern NH service area (Manchester, Nashua, Concord, Derry, Bedford, Salem), groundhogs most commonly den under backyard sheds, deck additions, front stoops, and detached garages built on crushed-stone pads. Stone walls and fencerows that cross open fields are classic NH den locations — the rocky structure provides instant cover and reduces burrowing effort. New Hampshire has a quirky historical footnote: the state Legislature in 1883 established a 10-cent bounty per woodchuck to protect agricultural crops, one of New England's earliest nuisance wildlife programs. Today the species is unprotected and can be removed year-round, but licensed WCOs handle colony removals and multi-animal situations.

Peak season

Active April–October; intrusion and garden damage peak May–August; new burrows most visible July–August after young disperse

You might actually have

Eastern chipmunk (much smaller ground burrows; single ~2-inch entrance with no mound)
Norway rat (2–3-inch ground holes near structures; no fan-shaped mound)

We serve these communities

ManchesterNashuaConcordDerryBedfordSalem

Hillsborough · Rockingham · Merrimack Counties

NH-licensed applicator · #782664
Same-day service
Family-owned since 2017

Service Area Map

Southern New Hampshire

When it's past DIY

When to call a Wildlife Control Operator (WCO)

Burrows under structures require both removal of the resident animal and installation of permanent exclusion — doing one without the other leads to rapid recurrence. A licensed WCO maps the full burrow system (including hidden plunge holes), removes the animal, and installs hardware-cloth exclusion that prevents re-entry by new animals. For burrows adjacent to a foundation, a WCO inspection also confirms whether the structure has been compromised.

Signals it's past DIY

When to call a pro

The burrow is directly under or adjacent to a building foundation, shed pad, or deck footing.
You have found multiple burrow entrances and cannot locate all plunge holes.
Live trapping has not resolved the problem after two weeks — a different individual may have moved into the burrow.
You suspect dependent young are present in April–May and need safe, legal removal.
A woodchuck bite has occurred — contact NH DHHS at (603) 271-4496 and document the animal; a WCO can assist with capture for observation.

Keep them out — prevention

Install L-bend exclusion fencing around all ground-level structures

Hardware-cloth aprons buried 10–12 inches deep with an outward L-bend are the single most effective permanent prevention. Install before you see a groundhog — retrofitting around an occupied burrow is harder than installing proactively.

Clear brush and debris from shed and deck perimeters

Groundhogs select den sites with nearby cover. Removing brush piles, stacked lumber, and dense shrubs from structure perimeters makes the site less attractive and helps you spot new burrowing activity early.

NH-specific

Inspect stone walls and fencerows bordering your yard

NH's abundant stone walls and rural fencerows are classic woodchuck den sites. A groundhog established in a stone wall 30 feet from your garden is a predictable garden problem every spring. Check these areas in April when groundhogs first emerge.

Not sure it's a groundhog?

A licensed NH technician can confirm the species and tell you honestly whether it's a DIY fix or a job for a pro — free inspection, same-day service across Southern New Hampshire.

Get a Free Inspection (603) 785-0118

Common Questions

Frequently asked questions

Sources(5)

[1]
Penn State Extension — Woodchucks
Body size and weight; litter size and timing; gestation; general biology
extensionverified 2026-06-30
[2]
SUNY ESF — Woodchuck
Burrow length (15–30 m); depth; entrance count; habitat description
academicverified 2026-06-30
[3]
Massachusetts Audubon / Mass.gov — Learn About Woodchucks
Body measurements; litter size; hibernation timing; diet
govverified 2026-06-30
[4]
Carnegie Museum of Natural History — Groundhog Architecture
~275 lb excavated soil per main entrance mound; burrow architecture and plunge-hole description
academicverified 2026-06-30
[5]
NH Fish & Game — Wildlife Control Operators
NH WCO licensing; nuisance wildlife regulations; groundhog unprotected status in NH
govverified 2026-06-30

Written & reviewed by

Verified

Daniel Brady

NH-Licensed Pesticide Applicator · License #782664 (NHDAMF, RSA 430)

Daniel Brady is the New Hampshire–licensed applicator behind Anchor Pest Services, a family-owned pest control company serving the Manchester area since 2017.

Verify license

Last updated 2026-06-30

New Hampshire pest control

Dealing with groundhogs in your home?

Anchor Pest Services identifies and handles groundhog problems across southern and central New Hampshire. Family-owned since 2017, NH license #782664.

Get a Free Inspection (603) 785-0118

NH-licensed applicators (#782664)
Same-day service · free inspection
Family-owned since 2017

Keep Exploring

Groundhogs in New Hampshire — Burrows, Damage & Control

The burrowing mammal that undermines NH foundations and decks

How to identify a groundhog and its burrow

The tells — key ID features

Size, to scale

Beaver

Muskrat

Large raccoon

Signs of a problem

10–12-inch entrance hole with a fan-shaped mound of excavated soil pushed to one side

Moundless 2–4-inch secondary holes nearby, often hidden in vegetation

Well-worn, flattened grass trails leading from the burrow to feeding areas

Garden crops grazed at ground level with clean angled cuts on stems

Gnawed or stripped bark on the lower 6–12 inches of young fruit trees or shrubs

Soil settling, cracking, or void under a deck, shed pad, or walkway

The real risks, calibrated

Undermining of foundations, sheds, decks, and walkways

Burrow hazard to people, equipment, and livestock

Garden and agricultural crop loss

Rabies — rare but reportable in NH

DIY — what works, what backfires

What actually works

What backfires

Groundhogs in New Hampshire — statewide and under your shed

When to call a Wildlife Control Operator (WCO)

Install L-bend exclusion fencing around all ground-level structures

Clear brush and debris from shed and deck perimeters

Inspect stone walls and fencerows bordering your yard

Not sure it's a groundhog?

Frequently asked questions

Dealing with groundhogs in your home?

Your next step

How to Get Rid of Groundhogs

Chipmunks in New Hampshire — ID, Signs & Control

Do chipmunks cause damage near foundations?