Signs of a Rodent Infestation on Long Island

As the weather turns cold, mice and rats move into Long Island homes looking for warmth, food and a quiet place to nest. Most infestations announce themselves weeks before anyone sees an animal — if you know what to look for. These are the signs we check first on every rodent call.

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The checklist

7 signs rodents are living in your home

Droppings. The most reliable sign. Small, rice-like pellets mean mice; larger, raisin-sized droppings mean rats. Look along walls, in cupboards, and under sinks — rodents run the same routes every night.
Scratching and scurrying at night. Rodents are busiest after dark. Scratching in walls, light running across the ceiling, or gnawing sounds in the attic almost always mean something is living in the structure.
Gnaw marks. Rodent teeth never stop growing, so they chew constantly: food packaging, stored items, wood, plastic pipes — and wiring, which is a fire risk. Fresh gnaw marks look light-colored; old ones darken.
Grease marks along walls. Rodents hug walls and squeeze through the same gaps until their fur leaves dark, greasy rub marks along baseboards, pipes and entry holes.
Nests in quiet corners. Shredded insulation, paper, fabric or cardboard gathered into a ball in the attic, basement, garage or behind appliances is nesting material — a sign they are settling in, not passing through.
A musty smell in closed spaces. A stale, ammonia-like odor in a pantry, closet or basement that was not there before often comes from rodent urine along their routes.
Your pet fixates on one spot. Dogs and cats hear and smell rodents long before people do. A pet that suddenly stares at one wall, appliance or corner every evening is worth paying attention to.

One sign on its own can be a false alarm. Two or more together — especially droppings plus sounds, or droppings that reappear after you clean — means an active infestation, not a visitor.

Where to check

The five places rodents hide first

The attic. Warm, quiet and rarely visited — check insulation for droppings, nests and runs worn into the material. The basement and cellar. Look along the foundation walls and around pipes and utility lines where they enter the house. Behind kitchen appliances. The warmth behind a stove, fridge or dishwasher, plus dropped food, makes this a favorite feeding stop. The garage. Stored boxes, pet food and a door that does not seal at the bottom are an open invitation. Around pipes and vents. A mouse can squeeze through a gap the size of a dime; a rat needs about half an inch. Every pipe, vent and cable entry is a possible door.

Mice or rats?

Why the difference matters

Mice are curious and range over a small area, so traps and bait placed along their routes work well. Rats are cautious of anything new, stronger, and able to cause real structural damage — and they often come in through lower entry points, including drains and foundation gaps. The treatment, the materials used to seal the home, and the follow-up schedule are different for each, which is why identifying the animal correctly comes before anything else. Our rodent control service starts with that identification.

What not to do: do not seal holes before the animals are out — you will trap them inside, and the problem gets worse and smellier. Do not rely on poison alone: it does not find the nest, and it does nothing about the gap they are walking through. And do not assume two traps from the hardware store will finish an established infestation — by the time signs are obvious, there is usually a nest and more than one entry point.

When to call

Call a licensed exterminator when…

You see droppings in more than one room, hear sounds in the walls or ceiling at night, find signs again after cleaning, spot any rat evidence at all, or find chewed wiring. Rodents breed through the winter indoors, so a small problem in the fall rarely stays small. Supra removes the rodents and seals the entry points in the same job — that sealing is what keeps them from coming straight back. We serve Nassau County and western Suffolk County from our base in Huntington Station.

Rodent control Emergency services Huntington Station

If pests return, so do we

Return visits at no additional charge. NY State DEC Licensed Commercial Pesticide Applicator, License #C2880113, Categories 7a (General Pest) & 8 (Public Health). Fully insured. Est. 2024 — 15+ years industry experience.

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FAQ

Common questions

How do I know if it is mice or rats?

Droppings are the quickest tell. Mouse droppings are small, about the size of a grain of rice. Rat droppings are much bigger, closer to a raisin. Rats also leave heavier gnaw marks and louder sounds. If you are not sure, send us a photo when you call — or book an inspection and we will identify it on site.

Can I handle a small rodent problem myself?

One mouse, caught early, sometimes. But visible droppings in more than one room, sounds in the walls, or signs that come back after cleaning usually mean a nest and an entry point you have not found. Traps alone do not close the hole they are coming through.

How fast do rodents multiply?

Fast. A single pair of mice can turn into dozens within a year, and they breed through the winter indoors. That is why a small sign in October becomes a real infestation by January if the entry points stay open.

Do you seal the entry points, or just remove the rodents?

Both. Removal without sealing is a short-term fix — new rodents use the same gaps. Every rodent job includes finding and sealing the entry points, which is what makes the result last.