Bobby BugsLong Island Pest Control
Rodents

House Mouse (Mus musculus)

Quick facts

The house mouse is the small gray rodent that moves into Long Island homes every fall. It weighs about half an ounce, fits through a gap the width of a pencil, and breeds fast enough that two mice in October can be a colony by January.

Size5 to 7 inches long including a 3 to 4 inch tail, about half an ounce
ColorGray to light brown, lighter belly
Look-alikesDeer mouse and white-footed mouse (two-toned, white belly, come in from wooded lots), juvenile rats (bigger feet and head)
Where you'll find itKitchens, behind appliances, basements, garages, attics, wall voids
Active on Long IslandYear round indoors; move inside in October, peak in November
Danger levelContaminates food, chews wiring, spreads bacteria

Long Island season

Mice move indoors on Long Island in October, as soon as overnight lows drop into the 40s, with calls peaking in November and a smaller second wave in early spring.

How to identify it

A house mouse is small, gray, with a tail about as long as its body and small feet. Droppings are about the size of a grain of rice, dark, with pointed ends, and you'll find them along walls, in cabinets, and under the sink.

Deer mice and white-footed mice, common on the North Shore and near wooded areas, are two-toned with a white belly and feet and tend to nest in attics and garages. Rats are much larger, with heavy feet and a thick tail.

Signs you have them

Why it matters

Mice contaminate every surface they cross with urine and droppings, and they chew through wiring, insulation, and stored belongings. A female can have 5 to 10 litters a year of 5 or 6 pups each, and the young can breed at 5 to 6 weeks old, which is why a small problem in October is a serious one by winter (UC IPM).

Can I handle it myself?

Sometimes, if it's one or two mice and you find the entry point. Snap traps placed along walls, no more than about 10 feet apart, with a small dab of peanut butter on the trigger, work better than anything sold as a repellent.

What most homeowners miss is the sealing. Mice fit through a 1/4 inch gap, and plastic, foam, rubber, and wood all get chewed through. Gaps need steel wool with caulk or metal (CDC, UC IPM). If you're still catching mice after two weeks, or you hear them in the walls, the entry points haven't been found.

How Bobby Bugs treats it

We inspect inside and out, trap the active runs, show you every entry point we find, and come back to check. Mouse treatment carries a 60-day written guarantee.

More on mouse extermination on Long Island.

Related answers

Frequently asked questions

How many mice do I have if I saw one?

Usually more than one. House mice rarely travel more than 30 feet from the nest, so a mouse in the open means a nest nearby, and by the time one is out in daylight the population is competing for food. Droppings are the better count: a pea sized pile in a cabinet corner is one to three mice, a tablespoon or more is an established population.

When do mice come inside on Long Island?

October, as soon as overnight lows drop into the 40s, with calls peaking in November and a smaller second wave in early spring.

Do mice go away on their own?

No. A house gives them food, warmth, and shelter, and they breed year round indoors. The population grows until something stops it.

What size hole can a mouse get through?

About 1/4 inch, the width of a pencil. Check where pipes, cables, and gas lines enter the house, the garage door seal, and gaps at the foundation.

Sources

Own a restaurant or manage a building?

Businesses and multifamily buildings need a recurring program, not a one-time visit. See how we handle restaurant pest control and pest control for apartment buildings.

Think you have house mice? Call (516) 509-6001 for a free written quote.

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