New York City is home to millions of mice, primarily house mice living inside buildings and white-footed mice inhabiting parks and green spaces. Whether you’re dealing with an unwanted roommate in your apartment or just curious about the rodents sharing your city, here’s what you need to know about the species, the health risks, and your rights as a tenant.
Which Mouse Species Live in New York
Three mouse species are common across New York State: house mice, white-footed mice, and deer mice. In the city itself, the two you’re most likely to encounter are house mice and white-footed mice.
House mice are the ones you’ll find in apartments, restaurants, and basements. Adults measure 2.5 to 3.75 inches long with a tail roughly the same length as the body. They have large ears, large eyes relative to their head, and a pointed nose. Their fur is uniformly grayish-brown on both the back and belly. House mice can live their entire lives indoors, which is why they thrive in a city of tightly packed buildings with easy access to food and shelter.
White-footed mice and their close relatives, deer mice, spend most of their time outdoors but move into structures from fall through spring. They’re about the same size and shape as house mice, with one easy tell: white fur on their bellies. If you’re finding a mouse in your apartment during cold months that has a distinctly lighter underside, it’s likely a white-footed mouse that came in looking for warmth.
How City Life Has Changed NYC Mice
White-footed mice living in New York City parks are genetically different from their rural counterparts. Research from the City University of New York found that mouse populations in individual urban parks, like those in Manhattan and the Bronx, have become distinct populations over time. Their estimated divergence dates line up with patterns of urbanization, meaning as neighborhoods were built up and paved over, mouse populations in remaining green spaces became isolated from one another.
The most striking finding involves diet. The majority of genes showing signs of adaptation in urban mice are involved in metabolic functions, especially dietary specialization. City mice appear to be using novel food resources or metabolizing nutrients differently than rural mice. In practical terms, generations of living on pizza crusts, garbage, and whatever else New Yorkers discard may have literally reshaped these animals at a genetic level. Each park’s mouse population has followed its own evolutionary path, making NYC parks something like islands of independent mouse evolution.
Health Risks From NYC Mice
A Columbia University study that genetically analyzed the droppings of house mice caught across New York City found a concerning lineup of pathogens. The mice carried several bacteria that cause gastrointestinal illness, including C. difficile, E. coli, Shigella, and Salmonella. Researchers also found genes for antimicrobial resistance to several common antibiotics, meaning some of the bacteria these mice carry could be harder to treat with standard medications.
The same study identified 36 viruses in the mice, including six previously unknown viruses. None of the viruses are known to infect humans, but some matched viruses that infect dogs, chickens, and pigs, suggesting cross-species transmission has already occurred at least once.
Hantavirus, which people sometimes worry about with mouse infestations, is extremely rare in New York. Since tracking began in 1993, the state has recorded only five cases total. Leptospirosis, a bacterial infection spread through animal urine, is more commonly associated with rats than mice in the city. NYC’s health department notes that the number of leptospirosis cases has increased in recent years, though the disease remains rare overall. Rats are the primary source, but the general advice applies to any rodent situation: avoid contact with areas where rodents urinate, clean contaminated surfaces with a one-part-bleach-to-ten-parts-water solution, and wash your hands thoroughly after any contact with areas where rodents may live.
Your Rights as a Tenant
If you’re renting in New York City, your landlord is legally responsible for keeping your apartment free of mice. The NYC Housing Maintenance Code places the duty squarely on building owners to keep premises in good repair and in compliance with health and safety standards. This applies to all multiple dwellings (buildings with three or more units) without exception.
The only situation where a tenant bears responsibility is if the infestation was caused by the tenant’s own willful act or gross negligence. Leaving food out carelessly might count, but the code is clear: even if a tenant is partly responsible, that does not relieve the owner of the obligation to address the problem. Your landlord cannot simply blame you and refuse to act.
For one- or two-family dwellings, the owner still has the same duty unless a written lease specifically shifts certain maintenance responsibilities to the tenant. Verbal agreements don’t count.
You’re also required to let your landlord or their pest control contractor into your apartment at a reasonable time to make repairs or inspect for code compliance. Refusing access can slow down the process and potentially shift some liability onto you.
Getting Rid of Mice in Your Apartment
New York City’s housing authority has moved toward integrated pest management, or IPM, which prioritizes finding and eliminating the root causes of infestations rather than just spraying pesticides. The core principle: if you don’t seal the holes and remove the food sources, no amount of poison will solve the problem long-term.
Sealing entry points is the single most important step. Mice can squeeze through gaps as small as a dime. Check around pipes under sinks, gaps where radiator pipes enter the wall, spaces around electrical outlets on exterior walls, and any cracks along baseboards. Steel wool stuffed into gaps works as a temporary fix. Caulk or expanding foam provides a more permanent seal. For larger openings, metal flashing or hardware cloth is more effective since mice can chew through foam over time.
Food storage matters just as much. Keep dry goods in sealed glass or hard plastic containers. Don’t leave pet food out overnight. Take garbage out regularly and use trash cans with tight-fitting lids. Even crumbs under a toaster or grease behind a stove can sustain a mouse population.
When traps are needed, snap traps baited with peanut butter remain the most effective option for individual apartments. Place them perpendicular to walls with the trigger end against the baseboard, since mice tend to run along edges rather than through open space. Glue traps work but raise animal welfare concerns and can be messy. Poison baits are generally discouraged inside apartments because mice can die in walls, creating odor problems, and the bait poses risks to children and pets.
If your landlord’s efforts aren’t working or they refuse to act, you can file a complaint with NYC’s 311 service. The city’s Department of Housing Preservation and Development can inspect the building and issue violations that compel the landlord to address the infestation.