Rodents are mammals with sharp incisors used to gnaw wood, break into food, and bite predators. They eat seeds or plants, though some types have more varied diets.

Rodents are nocturnal creatures, spreading diseases (such as salmonella and tuberculosis) by contaminating food intended for human consumption, and causing damage to buildings and property by gnawing and burrowing into structures.

Pest Species in New York:

House Mouse

Mus musculus

Mice cause all sorts of trouble, such as gnawing on walls and furniture, chewing electrical wires, and contaminating food.

They are typically come out at night in search of food and water. Although they’ll eat just about anything, they especially love grains, fruits, seeds, and pet food that’s been left out overnight.

Signs of a house mouse infestation include droppings, scratching noises, musky odors, gnaw marks, and runways (dirty, greasy smudges from their fur rubbing against floors and baseboards).

House Mouse

Size: 2 1/2″ – 3 3/4″ long (6 – 10 cm) from nose to base of tail

Color: Dusty gray to brown

Shape: Small, round body with a long naked tail, small rounded ears, and pointed snout

Identifying Features

Head: Slightly pointed nose, small eyes, and small rounded ears

Teeth: Long, protruding front teeth with a notch on the inner surface of the upper incisors

Fur: Small, round body with short fur that’s uniformly grayish-brown; some individuals may have a light grey or cream-colored belly

Tail: Gray or light brown (similar to its fur); mostly hairless

Norway Rat

Rattus norvegicus

Norway rats, colloquially known as “brown rats” or “sewer rats,” are known to infest buildings, damage property, contaminate food, and spread disease.

Over the centuries, their diets and behaviors have evolved alongside modern human society, allowing them to thrive in dense, urban environments like New York City (which is home to as many as 3 million rats, according to a statistical analysis we conducted in August 2023).

Norway Rat

Size: 8″ – 11″ long (20 – 28 cm) from nose to base of tail

Color: Gray or brown/black mix

Shape: Long, stout body with a long scaly tail and large ears

Identifying Features

Head: Blunt nose and large, pink ears

Teeth: Large, chisel-shaped incisors that leave prominent teeth marks on objects and surfaces

Fur: Long, stout body with coarse and bristly fur that’s mostly brown or grey, except for a tan or light gray underbelly

Tail: Pink or tan-colored; covered in tiny circular rows of scales