Common Species of Rodents Found on Long Island

Rodents ranging from tiny mice to larger rats are common trespassers on Long Island properties. These adaptable pests utilize openings as small as a dime to a quarter to gain access to structures. Once inside, they compromise the safety of your home by compulsively gnawing materials and contaminating food sources. The following sections provide Nassau County and Suffolk County residents with essential details on each species' appearance and behavior, enabling accurate rodent identification to determine the appropriate rodent control measures.

1. 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.

2. 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.

3. 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.

4. The 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.

5. The 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 have a knack for nibbling on all sorts of things, like electrical wires, insulation, and even walls, which can lead to some pricey repairs and safety concerns for homes and businesses. When insulation gets damaged, it might mean higher energy bills and a less cozy space. While having rodents around can be a bit of a hassle, it's important to address them to keep your property and loved ones safe.

Both rats and mice can spread also disease through food contamination, their droppings and urine. These diseases include salmonella, hantavirus, plague, leptospirosis, and Lassa fever.

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.