Groundhog

Groundhog Removal in Nassau County: Protecting Foundations and Gardens from Burrowing Damage

May 2, 2025·10 min read

Groundhogs — also called woodchucks (Marmota monax) — are among the most common nuisance wildlife complaints from Nassau County homeowners. These large burrowing rodents are highly adaptable to suburban environments, and their tendency to establish burrow systems under concrete structures, foundation slabs, and stoops creates genuine structural risk for Long Island homes. Understanding groundhog behavior, the specific damage they cause in Nassau County's residential landscape, and the most effective removal and exclusion strategies will help homeowners resolve these problems permanently.

Groundhog Biology and Nassau County Habitat

Groundhogs are the largest members of the squirrel family in the northeastern United States, typically weighing 5 to 14 pounds. They are true hibernators — among the few North American mammals that enter deep torpor characterized by significantly reduced body temperature, heart rate, and respiration — which means Nassau County groundhogs are active only from late February or March through October or November.

Nassau County's residential landscape provides ideal groundhog habitat: short lawns for foraging, abundant vegetable and ornamental gardens, and numerous concrete and wood structures that offer protected burrowing sites. Groundhogs in suburban Nassau County establish burrow systems under decks, stoops, concrete pads, garden sheds, and occasionally foundation walls of attached garages and older homes.

A groundhog burrow system is more extensive than most homeowners realize. The main tunnel typically runs 25 to 30 feet, at a depth of two to six feet. Multiple plunge holes (vertical shafts without excavated mounds, used as emergency exits) may be located 10 to 20 feet from the main entrance. Secondary tunnels extend off the main corridor. The total displaced soil volume from a single burrow system can exceed 700 pounds — and this excavation, when directed under a foundation, stoop, or concrete slab, creates voids that lead to settling and cracking.

Foundation and Structural Damage in Nassau County

Nassau County's post-war housing stock — the Cape Cods, split-levels, and ranch homes built in the 1950s through 1970s — is particularly vulnerable to groundhog foundation damage. Many of these homes were built on concrete block or older poured concrete foundations with crawl spaces or partial basements. Groundhog burrows that extend under these foundations displace the supporting soil, creating the conditions for:

• Foundation settling and cracking: Voids under foundation footings cause differential settlement, leading to visible cracks in foundation walls, sticking doors, and cracked interior walls.
• Stoop and step damage: Concrete stoops are almost universally unfootered in Nassau County homes of this era — they sit on the soil surface. Groundhog burrowing directly beneath stoops removes supporting soil, causing tipping, sinking, and concrete cracking.
• Deck post undermining: Wood deck posts buried in the soil are particularly vulnerable. As the burrow system expands, supporting soil is removed and deck framing shifts.
• Driveway and walkway cracking: Shallow burrow tunnels running under asphalt driveways or concrete walks create invisible voids, leading to surface cracking and subsidence.

Garden and Landscape Damage

Groundhogs are voracious herbivores with catholic tastes. A single groundhog can devastate a Nassau County vegetable garden in a matter of days, consuming or damaging beans, peas, lettuce, broccoli, melons, squash, and most other common vegetables. They are also responsible for significant damage to ornamental plants — hostas, black-eyed Susans, and other perennials are consumed at the root level.

Standard chicken-wire or low garden fencing is not effective against groundhogs. They burrow under it within days. Effective garden protection requires an L-shaped footer — fencing installed vertically above ground and then bent horizontally outward underground for 12 to 18 inches — which prevents the animal from digging directly under the fence base. Electric fencing is also highly effective and can be installed around garden perimeters for relatively low cost.

Trapping and Removal in Nassau County

Groundhogs are classified as an unprotected species in New York State, which means Nassau County property owners may trap and remove them without a state permit. However, trapping for hire requires a NYSDEC Nuisance Wildlife Control Operator license. Live cage trapping is the standard removal method.

Effective groundhog trapping in Nassau County requires:

1. Trap placement: Cage traps should be placed at or directly in front of the main burrow entrance, aligned with the burrow opening so the groundhog does not have to change direction to enter. Traps placed at angles or in random yard locations are much less effective.
2. Bait selection: Fresh vegetables are the most effective bait — cantaloupe, fresh corn, and leafy greens work well. Peanut butter with apple slices is also effective.
3. Daily monitoring: Traps must be checked at least once daily to prevent unnecessary stress or injury to captured animals.
4. Burrow system mapping: All plunge holes and secondary entrances must be identified before trapping begins. Groundhogs that detect a trap at the main entrance will use alternate exits and may not be captured.

Exclusion After Removal

Trapping removes the individual groundhog, but it does not prevent reinfestation. An unoccupied burrow system under a Nassau County foundation or deck is an immediate attractive nuisance for the next groundhog to move through the area. Exclusion after removal is essential:

• Burrow filling: Burrow entrances and plunge holes should be backfilled with compacted soil and tamped firmly. The main tunnel can be probed with a long rod before filling to confirm the groundhog is no longer present (freshly dug, loose soil in the tunnel indicates recent activity).
• Hardware cloth exclusion aprons: Around decks, stoops, and shed foundations, 16-gauge hardware cloth installed as an L-shaped apron — vertical above grade and horizontal underground — prevents future burrowing attempts. The underground horizontal section should extend at least 18 inches outward from the structure perimeter.
• Foundation ledge protection: Where foundation footings are exposed or where groundhog burrowing has occurred along a foundation wall, a concrete ledge or continuous hardware cloth barrier along the foundation perimeter may be warranted.

For Nassau County homeowners dealing with recurring groundhog problems — particularly those with evidence of burrowing near foundations — contact Wildlife NY at (516) 447-4673 for a free inspection and a permanent exclusion plan.

Frequently Asked Questions