The short version
Rodent control in New York works from the outside in. Norway rats and house mice are the two species you will meet, and both get in through openings a quarter inch and wider, which the CDC says is all a mouse needs. Seal those in metal, trap what is already inside, then remove the food and water keeping them there.
- New York's density means the source is often a neighboring building, not your kitchen.
- Norway rats work low, in basements, cellars and burrows; mice travel wall cavities upward.
- Sealing gaps of a quarter inch or more is the step that ends a repeat problem.
- Fall entry peaks from September through November as temperatures fall toward 27 degrees.
- State rules let property owners take mice and rats without a permit.
If you have kept traps out for a while with no drop in catches, start with the sealing sections. Supers and managing agents trying to figure out why one line of apartments keeps reporting mice. Restaurant and shop operators with an alley issue and an inspection on the calendar. Owners of small buildings dealing with a cellar problem. Apartment dwellers who found droppings under a sink and want to know what to ask the building for.
What to look for
Two species account for nearly all of it. Norway rats are the heavy, blunt-nosed ground dwellers that burrow in soil, live in cellars and sub-basements, and travel sewer and utility connections. House mice are small, curious, and live entirely indoors once they arrive, nesting in wall cavities, behind appliances and inside stored boxes. Density is what makes New York different from a suburb. Rats forage a hundred to five hundred feet from the nest, and in a city block that radius can cover several buildings, a restaurant loading area and a park edge. Mice move between apartments through shared chases, so a single unit treated alone rarely stays clear. Weather adds to it. The city sits at an average elevation around 33 feet and takes about 49 inches of rain a year, and a heavy storm can flood burrows and cellar spaces, which pushes rats upward and inward into occupied rooms.
- 1Dark droppings the size of rice grains inside a cabinet or behind the stove.
- 2Grease-darkened rub marks along a baseboard or where a pipe passes through a wall.
- 3Gnawed corners on a cabinet door, a food container or a package left on the floor.
- 4Scratching inside a wall cavity that moves vertically between floors.
- 5Fresh burrow openings in a courtyard, tree pit or beside a cellar door.
- 6A stale ammonia smell under a sink that comes back after cleaning.
- 7Droppings on top of a trash room floor edge, near where bags are staged.
Why it’s worth acting soon
- Rat urine in wet cellars is one way leptospirosis reaches people, and the CDC lists rodents among carriers.
- Chewed wiring inside old walls is difficult to trace and dangerous to leave alone.
- A Norway rat female weans 20 or more offspring a year, so delay compounds fast.
- Contaminated food surfaces in a commercial kitchen turn a pest issue into a compliance issue.
- Mice spreading through a building line means a bigger, more disruptive job later.
1/4 inchSmallest opening a mouse can enterCDC 20 or moreNorway rat offspring weaned per female each yearUC IPM Treatment options and typical costs
Interior exclusion
Quoted after inspection
Openings a quarter inch and wider get closed with copper mesh, sheet metal, mortar and hardware cloth: pipe chases under sinks, gaps behind radiators, holes cut for cable and gas lines, and the space around a tub trap access panel. In an apartment this is the highest value work and it is often overlooked entirely.
- Time
- Depends on how many penetrations each unit has
- Best for
- Mice in apartments and shared walls
Cellar and foundation sealing
Quoted after inspection
The base of the building gets treated as a barrier: cellar doors and hatches made tight, floor drains screened, unused pipe penetrations mortared, and vents covered in quarter-inch hardware cloth. Norway rats enter low, so a building that closes its cellar properly cuts off the main route into everything above it.
- Time
- Set by cellar access and the number of openings found
- Best for
- Rat activity in basements and sub-basements
Trapping program
Quoted after inspection
Traps go on mapped runways and get serviced until nothing is caught. Rats avoid unfamiliar objects, so traps often sit in place unset until the animals accept them, which makes a rat job slower than a mouse job. The catch log is your proof that the population is shrinking rather than being resupplied.
- Time
- Runs until the catch log reaches zero
- Best for
- Any confirmed activity inside the building
Exterior burrow and station work
Quoted after inspection
Locked stations along the building line and treatment of active burrows in courtyards, tree pits and rear yards intercept rats before they reach a wall. Because trash staging drives the food supply, this usually comes with changes to how and when refuse is put out. Ask how pets and children are protected.
- Time
- Ongoing; ask how often stations are checked
- Best for
- Buildings with yard, alley or courtyard rat pressure
Prices are typical published ranges. Ask what’s included before you compare quotes.
Bathroom vanities hide the same plumbing gaps as the kitchen. A quick look with a flashlight shows droppings or rub marks long before you see a mouse.How rats move through a New York block.
When a rat cannot get in and cannot eat, it moves on to somewhere that has not done the work. Then close the building at grade: cellar doors gasketed, hatches latched, floor drains screened, and every abandoned pipe penetration mortared shut. Take away the harborage by clearing clutter and treating burrows so you can see which ones reopen. Take away the food by changing when and how refuse is staged. What works is layered. Control that ignores the block only moves the problem around. The food supply might be a restaurant's staged bags two doors down or an overflowing corner basket. That foraging radius, a hundred to five hundred feet, is why a spotless building can still have rats at the door. Burrows go into soft ground, which in New York means tree pits, courtyards, rear yards, planters and the soil beside a cellar entrance, and the animals travel out from there to feed and back again before dawn. A Norway rat colony does not live in your building so much as in your block.
Why mice spread through an apartment line.
If a managing agent will only authorize one apartment, seal yours anyway, because it stops your unit from being a destination even while the building sorts itself out. Pair that with trapping in the units showing activity. The fix is unglamorous: pull the escutcheons and access panels, pack copper mesh tight into every penetration, seal over it, and do it in every unit on the line at the same time. You can trap out the mice in 4B, and 4C will resupply it through the same chase, because a quarter-inch opening is all the passage required. This is the reason single-unit treatment so often disappoints. One apartment reporting mice usually means several apartments have them and only one tenant is paying attention. They travel vertically through the chases cut for risers, horizontally along the space above dropped ceilings, and out into apartments through the gaps around pipes under sinks and behind radiators. Mice in a multi-unit building behave like water in a plumbing system.
Fall is when rodents head indoors. Leaf piles against the foundation hide burrows and gaps, so clear them and walk the wall before the first cold snap.What rain and low elevation do to rodent activity.
Keeping cellar storage off the floor and on shelving makes evidence visible early, which matters because a population that establishes in a sub-basement is far more work to remove than one intercepted early. Check cellar corners, behind stored material and around floor drains, since a drain that has lost its grate becomes a doorway once water recedes. The practical response is to inspect after major storms rather than waiting for droppings to accumulate. Usually an existing one simply relocated. People assume a new colony arrived. They move to the nearest dry, warm space, which is often a sub-basement, a boiler room or a utility chase. When a burrow floods, the rats living in it do not disappear. New York averages about 49 inches of rain a year and sits at an average elevation near 33 feet, so heavy storms can fill burrows and back water up into cellars. One of the most common reasons a quiet building suddenly gets loud is weather.
Renters, owners and who is responsible.
Ask for both quoted separately so you can see the difference. Set the one-time cost of closing the cellar and the chases against what an open-ended monthly service adds up to over a few years, since the monthly plan keeps numbers tolerable without ever fixing the route. For small building owners, the comparison is worth making. When a pest control technician visits, ask for a copy of the service report, since it lists the entry points found and becomes the evidence that sealing was recommended and not done. Photograph droppings with a date visible, write down where and when you hear activity, and send requests by a method that leaves a record. Verbal requests vanish. Where it goes wrong is documentation. Food storage, dishes, trash timing and clutter belong to whoever lives in the unit. Holes in walls, gaps at pipe chases, broken cellar doors, missing drain grates and damaged door sweeps are structural, and structural items belong to the owner or the building. The split follows the same logic as any other repair.
Cleaning up after rodents without making it worse.
If nesting material has soaked into stored belongings, throw them out rather than trying to salvage them. Rodents spread leptospirosis, rat-bite fever and salmonellosis directly according to the CDC, and cellar cleanup often involves standing water where rat urine has collected. In cellars and boiler rooms, add ventilation and consider handing the job over, because volume changes the risk. Wear gloves throughout. Wipe up with paper towels, bag the waste, and wash your hands afterward. Mix about 1.5 cups of household bleach into a gallon of water, spray the droppings and nesting until they are visibly wet, and let them soak for five minutes. Ventilate the space for 30 minutes before you start. The CDC procedure is short. Dried droppings and nesting break apart when disturbed, and a broom or a vacuum sends that material into the air of a small apartment. Cleanup is the step people rush, and it is the one with a health consequence attached.
What affects the price
- Whether the job covers one apartment or the whole building line.
- Cellar and sub-basement access, and how much clutter has to be moved first.
- The number of unsealed pipe chases and abandoned penetrations in old plumbing runs.
- Rats versus mice, since rat work extends outdoors into yards and trash areas.
- Whether trash staging can actually be changed, which drives repeat pressure.
- How many service visits the trapping phase needs before catches stop.
- Commercial versus residential scope, since kitchens have more equipment to work around.
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What's your biggest concern about rodents?
When to call for help
Ask the provider to inspect the cellar and the unit before quoting, ask which openings they found and what will close each one, and ask for exclusion to appear as its own line rather than being bundled into a monthly plan. Restaurants and food shops should act on first evidence rather than waiting. In a multi-unit building, call the moment two apartments report the same thing, because that means the animals are using shared cavities and single-unit treatment will not hold. Call when you see a rat rather than a mouse, when activity is inside a wall or between floors, or when droppings appear in more than one room.
What you can do yourself
In an apartment you can do more than you think. Pull the plate under the sink, look for the gap where the drain and supply lines pass through the wall, and pack it with copper mesh before sealing over it. Put dry goods in glass or metal, keep the floor clear at night, and set snap traps flush against the wall where droppings are heaviest rather than out in the open. The limits are the building and the species. Cellars, sub-basements, courtyard burrows and shared chases are not yours to fix, and rats are not a casual project because they avoid new objects and range across the block. Cleanup of heavy droppings needs the CDC wet-down method and gloves rather than a broom. The practical division in New York is that you seal your own unit and manage your own food, and the building handles the cellar, the trash area and everything structural.
Rodents in New York
New York was founded in 1624, and centuries of building, rebuilding and retrofitting have left an enormous number of holes: abandoned gas line penetrations, chases cut for new plumbing, and cellar walls patched many times over. That, more than anything, is why rodent work here is a sealing job. Average elevation around 33 feet and about 49 inches of rain a year mean cellars and burrows can take on water in a heavy storm, which pushes rats into occupied space. Median home value across the city is roughly $732,000, so the money at stake in a wall cavity is not small. Add an urban density that keeps food available around the clock and a fall entry season running September through November, and you get a city where the buildings that stay clear are simply the ones that were closed properly.
Local research
Rodents in New York, NY: what the public record shows
Before you compare quotes, it helps to know which rodents actually live in New York, when they are busiest around New York, and what the state figures look like. Everything below links to the agency or university page it came from.
Leptospirosis cases, New York City (YTD 2026 vs 2025, week 13)
NYC reports separately from the rest of the state.
CDC NNDSSRodent species recorded in New York
- House mouse (Mus musculus) — Enters at 1/4 inch; 5-10 litters per year; eats about 200 small meals a night.
- Norway rat (Rattus norvegicus) — Burrowing rat of basements, sewers and ground floors; tail shorter than head plus body.
When rodents are busiest around New York
Fall entry (Sept-Nov). Norway rats and house mice move indoors as temperatures drop.
Based on New York’s humid subtropical climate profile.
Rules that apply in New York
For context, nationally
- 1/4 inch (the width of a pencil) — Smallest gap a mouse can enter. CDC
- 890; 35% fatal; 94% west of the Mississippi — Hantavirus cases reported since 1993 (through 2023). CDC
Sources: CDC NNDSS; CDC National Notifiable Diseases Surveillance System; New York State DEC; CDC; Pest Notes: House Mouse; Pest Notes: Rats. Figures are quoted as the source prints them. How we check our sources
Simple ways to keep rodents away
- Pack copper mesh into pipe chases under sinks and behind the radiator before sealing over it.
- Keep dry food in glass or metal rather than the original cardboard and plastic.
- Take trash out at the latest reasonable time, since staged bags feed the block.
- Ask the building to keep cellar doors and hatches closed and gasketed.
- Screen floor drains in laundry and boiler rooms with metal grates that stay put.
- Report chewed holes and open chases in writing so repairs get recorded.
- Keep courtyard and tree pit soil clear of clutter so burrows are visible.
- Check gaps around a window air conditioner where the sleeve meets the wall.
A good rodent quote lists the inspection, the number of trapping visits, each opening to be sealed and the material for it, and any cleanup.Did you know?
Rats do not need a wide opening to start with, since they gnaw a quarter-inch hole larger until it fits.
New York State outside the city logged one hantavirus case in the 2026 federal tally through early May, a reminder that the virus is rare in the East but not absent.
Rat-bite fever, salmonellosis and lymphocytic choriomeningitis are on the CDC list of illnesses rodents spread directly.
Questions people ask
What kinds of rodents are in New York buildings?
Norway rats and house mice, the two species listed for New York, account for nearly every call. Rats mostly stay low, in cellars, sub-basements, courtyards and burrows. Mice live inside year round and travel between units through wall and ceiling cavities. Identifying which one you have changes the plan, because rats are wary of new objects and often need traps left unset at first.
When is rodent activity worst in New York?
Entry peaks in the fall, roughly September through November, as New York nights cool toward a winter low near 27 degrees and animals look for heated space. Activity does not stop after that, since heated buildings let mice breed all winter. Heavy rain is the other trigger, because a flooded burrow or cellar sends rats upward into occupied space.
Can I trap rats and mice myself, or do I need a permit?
State wildlife rules allow property owners to take mice and rats without a permit, with the Allegheny woodrat as the exception. That covers snap traps in your own space. It does not cover the parts of a rental you do not own, and it does not make poisons a good idea around pets and children in a dense building.
Is leptospirosis a real risk from city rats?
It is uncommon but it is tracked here. Federal surveillance recorded three leptospirosis cases in New York City in 2026 through week 13, against one in the same stretch of 2025, and New York City reports separately from the rest of the state. Rats are a key urban reservoir, and exposure usually comes through water or soil contaminated by their urine.
Should I be worried about hantavirus in the city?
Practically no. The CDC counts 890 cases nationally since 1993, with about 94 percent occurring west of the Mississippi, and the exposure comes from deer mice in sheds, cabins and garages rather than urban apartments. The cleanup method still applies to any droppings, since dry sweeping puts particles into the air regardless of species.
My super keeps setting traps. Is that enough?
No, and the catch count proves it. Traps remove animals without changing the building, so as long as the chases and cellar openings stay open, the population outside keeps replacing what is caught. Ask in writing for the specific holes to be sealed with metal or mortar, and ask for the pest control service report, which names the entry points found.
Why do mice show up in my apartment when I keep it spotless?
Because in shared buildings the food source and the entry point are often somewhere else. Mice travel through wall cavities and pipe chases from a unit, a trash room or a restaurant space that is not clean, and they enter yours through a quarter-inch gap around a pipe. Sealing your own penetrations is the fastest thing you personally can do.
How long does a rodent job take in a building like mine?
There is no fixed timeline, because it depends on how many openings need sealing and how quickly catches fall. Mice in a single unit usually clear faster than rats or a problem spread across several apartments. Sealing happens early, trapping runs until the catch count reaches zero, and cellar work is scheduled around access. Be wary of a quick promise on a building-wide problem from anyone who has not inspected the cellar.
Nearby cities
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Sources (6)
The facts in this article come from the public sources listed above. Every home is different, so ask the company you talk to about pricing and what’s included. Published by Rodent Exterminator · Updated October 11, 2026 · How we write these guides