Common Rodents Found on Long Island

Rodents are one of the most common pests found in homes and businesses across Long Island. Mice, rats, and other rodents can enter structures through openings as small as a dime and quickly establish nests inside walls, attics, and storage areas.

Once inside, rodents contaminate food, damage insulation and wiring, and reproduce rapidly if the problem is not addressed. Understanding the most common rodent species found in Nassau County and Suffolk County can help homeowners recognize early warning signs and determine the best rodent control approach.

House Mouse

The House Mouse is the most common rodent found in Long Island homes and commercial properties. Its presence often signals a need for immediate intervention due to its rapid reproduction rate.

• Appearance: Small, slender body (2.5 to 3.5 inches long, excluding the tail). Typically, light brown or gray with a cream-colored belly, large ears, and a pointed snout.

• Behavior: Highly curious and active breeders, capable of producing multiple litters per year. They are adept climbers and only need a small opening (about 1/4 inch) to gain entry. Their droppings are small and rod-shaped.

• Location: Nests in secluded, dark, indoor spaces near food sources, such as wall voids, attics, cabinets, and stored items in basements and garages.

Deer Mouse

Often mistaken for the House Mouse, the Deer Mouse is primarily a woodland species but will enter suburban and rural homes, especially during cold weather. Its key concern is its role in disease transmission.

• Appearance: Reddish-brown to grayish brown above and a stark white belly and white feet. They have large, dark, protruding eyes and large ears.

• Behavior: Excellent climbers and jumpers. Unlike the House Mouse, they tend to store large amounts of seeds and nuts. Their droppings are smaller and often concentrated in one area.

• Location: Primarily found outdoors in wooded and brushy areas. They often enter homes in the fall to nest in attics, chimneys, and walls of homes adjacent to natural areas.

Norway Rat

Also known as the brown or common rat, the Norway Rat is a destructive and widespread pest across Long Island. Its larger size makes it capable of inflicting significant damage to structures.

• Appearance: Large, heavy body (7 to 9.5 inches long). Shaggy brown or grayish-brown fur, a blunt nose, small ears, and a tail that is shorter than its body.

• Behavior: Primarily ground-dwelling, building elaborate burrow systems outdoors near foundations, under sidewalks, and in sewer systems. They gnaw constantly to keep their teeth filed, which can damage pipes and electrical wiring.

• Location: Found in outdoor burrows, crawl spaces, utility tunnels, and the lower levels of structures in high-density areas of Suffolk County and Nassau County. They typically enter buildings through larger openings in the foundation.

Eastern Gray Squirrel

While generally considered wildlife, the Eastern Gray Squirrel is a common rodent pest responsible for extensive exterior and attic damage across Long Island.

• Appearance: Gray coat with a white underside and a large, bushy tail.

• Behavior: Squirrels are notorious for gnawing on eaves, soffits, and roof vents to create entry points into attics for nesting, especially in the cooler months. Once inside, they can damage electrical wiring and insulation.

• Location: Highly visible outdoors in trees and parks but often become pests when they seek shelter in the upper areas of homes and businesses.

Eastern Chipmunk

The Eastern Chipmunk is a smaller rodent frequently encountered in suburban landscapes, such as in Suffolk County, causing property damage through its burrowing habits.

• Appearance: Small with distinctive facial and back markings: five dark brown to black stripes separated by lighter stripes.

• Behavior: They are diurnal (active during the day) and constantly forage for food, storing it in expandable cheek pouches. They are prolific burrowers, creating extensive tunnel systems with multiple exit holes.

• Location: Yards, gardens, under patios, decks, and near foundations. Their burrows can compromise the stability of walkways, retaining walls, and concrete slabs.

How Dangerous are Rodents?

Rodents can cause serious problems when they enter homes or businesses. Mice and rats constantly gnaw on materials to keep their teeth trimmed, which can damage insulation, wood framing, and even electrical wiring.

Rodents can also contaminate food and surfaces with droppings and urine. Some species are associated with diseases such as salmonella, hantavirus, leptospirosis, and other pathogens that can pose health risks if infestations are not addressed promptly.

How Do I Prevent a Rodent Infestation?

To prevent rodent infestations in Long Island, follow these DIY rodent control tips:

• Proper Food Storage: Keep all food, including pet food, in airtight containers to discourage rodent presence.

• Secure Your Garbage: Ensure all indoor and outdoor garbage bins have secure lids that close properly.

• Seal Entry Points: Even a tiny gap is an open invitation to rodents. Mice can fit through openings as small as a dime, while Norway rats can squeeze through gaps the size of a quarter.