Pest Control in New York City

What makes pest control in New York City a different job?

Shared infrastructure. In this city almost nobody occupies a whole building, and the parts of a building that carry pests are exactly the parts no occupant controls.

Think about what an apartment actually is. It is a volume of air bounded by surfaces that belong to somebody else. Behind the kitchen cabinets is a wall shared with the next apartment. Under the floor is a slab shared with the apartment below. Inside that wall is a stack carrying waste and supply for every kitchen above and below. Somewhere near the bathroom is a chase that runs from the cellar to the roof. Down the hall may be a chute that drops refuse from every landing into a compactor. Out the back is a party wall shared with the building next door, and under the front is a cellar with a drainage connection to the street.

Every one of those is a pathway. None of them stops at an apartment door, and none of them is within the reach of the person living behind that door.

That is the whole of the difference, and it produces a specific and very common failure. A resident reports a problem. A technician attends, applies material, and the problem in that apartment stops. Within weeks it reappears there or turns up next door, above, or below. Nothing was done badly. The treatment acted on the animals in one volume of air while the population occupying the building carried on, and the pressure applied in one place simply redistributed it.

Research on proactive integrated pest management in multi-unit housing describes the mechanism directly: pests disperse from high-density units into units next to them or otherwise structurally continuous with them. In the same work, several of the most severe infestations were only found because every unit was being monitored, rather than only the ones that had complained. Complaint-driven service maps tolerance, not infestation.

The conclusion that follows is not a sales position, it is arithmetic. In a shared-wall, shared-riser building the only intervention that changes the outcome is one applied to the building. Everything else is maintenance of a steady state.

How do pests actually move through a New York building?

Along six routes, and they are the same six in a 1900 tenement, a 1929 elevator building and a 1965 tower — only the detailing changes.

Plumbing chases and risers. Waste stacks, supply risers, steam risers, gas lines and electrical feeders all run from cellar to roof and pass through every floor slab on the way. Where those penetrations were firestopped and sealed, they are nothing. Where they were sleeved and packed with whatever was to hand, or left open around the pipe, each is a continuous warm shaft with an opening into a cabinet or a wall cavity at every level. Mice prefer this route to any exterior one. German cockroaches move through the gaps of a millimeter or two around pipe penetrations and escutcheons; bed bugs use the same voids and travel through electrical conduit.

Party walls and joist pockets. In attached buildings the floor joists of both neighbors bear into the shared masonry wall between them, and the recess cut to receive each joist end was rarely sealed on nineteenth-century work. The result is a row of horizontal voids at every floor level connecting one building to the next. It is why a rodent or bed bug problem in one rowhouse appears next door within weeks, and why work that stops at your own front and back walls is half a scope.

Compactor chutes and refuse rooms. A chute is a vertical shaft with a hopper door on every landing, warm, damp and continuously supplied with food, ending at a compactor. Hopper doors that do not seat, a breached chute wall or a failed compactor room floor drain give the building an internal food corridor running its full height.

Cellars, vaults and areaways. Cellar hatches and areaways open directly onto the sidewalk. Building vaults extend under the public sidewalk on many blocks; NYC DOT licenses them, requires 600 PSF live loads on sidewalk doors, gratings and covers, and can order an abandoned vault filled in. A disused vault is a large dark void with a cellar connection and a grating to the street.

Drainage from below. Rats commonly enter buildings not from the street but from underneath, through deteriorated house traps and broken or disconnected drain lines. This is the single most under-diagnosed route in the city, because it is invisible from outside and entirely unaffected by exterior baiting.

Block interiors. In rowhouse neighborhoods the rear yards of a whole block back onto one another and form a single continuous habitat — soil to burrow in, cover to move under, fences that are barriers to people and irrelevant to animals, and a food supply that only has to be reliable at one or two properties for the entire interior to support a population.

What does the city’s building stock look like?

Layered, and the layers behave differently enough that the survey changes with the era.

Rowhouses, roughly 1830 to 1910. Brick or brownstone-fronted, three or four stories, the main floor raised above the street behind a stoop, a cellar partly below grade with an areaway in front and a yard behind. The Landmarks Preservation Commission’s rowhouse manual is direct about the underlying vulnerability — water is the eventual cause of most masonry deterioration — and explains the specific failure of brownstone: veneer set with the stone’s grain running vertically lets water into the bedding layers, where it freezes and forces the stone apart layer by layer. That spalling opens the wall, and an open wall holds water against concealed timber.

Tenements, roughly 1870 to 1929. Narrow, deep, walk-up buildings with stacked kitchens and bathrooms on shared lines, light shafts, and a century of piecemeal service upgrades cut through the structure. Yorkville east of Third Avenue was built this way for German, Czech, Slovak, Hungarian and Irish families from the 1880s onward.

Pre-war elevator apartment houses, roughly 1900 to 1940. Masonry shells with floors framed into them, generous plans, steam heat and vertical service runs threaded up through the structure. These are the buildings where chase sealing pays the largest dividend, because the chases are long, warm and continuous.

Post-war and mid-century blocks. Many of these replaced tenement rows — on the Upper East Side, high-rise construction began arriving in the 1950s after the elevated railway came down. Compactor chutes, central refuse rooms and larger service cores are standard, and those systems become the dominant internal pathway.

Recent construction. Better firestopping in principle, and in practice a new building’s problems arrive with its occupants and its refuse handling rather than through its fabric.

The historic-district layer sits across all of this. Brooklyn Heights was designated New York City’s first historic district in 1965. Park Slope’s district, designated in 1973 and extended in 2012 and 2016, now covers roughly 2,575 buildings and is the city’s largest landmarked neighborhood by building count. Five separate districts sit inside the Upper East Side alone. Landmark protection shapes exterior work and leaves the cellar, areaway, rear elevation, party-wall and roof-void work — which is most of what matters — untouched.

Which pests dominate in the city, and when?

Four carry the volume, and each has a route rather than merely a habit.

Norway rats are a street, cellar and drainage problem. The Health Department’s framing is the useful one: rats need food, water, shelter and safe ways to move around, exposed garbage attracts them, and property owners are legally required to keep them out. The department carries out over 150,000 rat inspections a year, and in some areas nearly every property is inspected annually. Four Rat Mitigation Zones were designated in July 2023 — Bronx Grand Concourse; Bushwick, Bed-Stuy and Prospect Heights; West, Central and East Harlem; and the East Village, Lower East Side and Chinatown — covering 37,545 properties. Between January and June 2025, 36,263 initial inspections across those zones produced 6,583 Commissioner’s Orders to Abate, an 18 per cent failure rate, down from 24 per cent the previous year. Pressure rises visibly through autumn and winter. See rodent control.

House mice are an interior problem, resident year-round with an autumn influx. They travel the chases and party walls, need about a quarter of an inch, gnaw softer material to widen what is smaller, and climb masonry and brick without difficulty.

German cockroaches are year-round and centered on the shared wet line. The work is monitoring in every unit on the stack, targeted material where the population actually is, and sealing the harborage — pipe penetrations, escutcheons, cabinet toe kicks and the voids above and behind kitchen runs. Cellars and refuse rooms produce American and Oriental cockroaches instead, which are drainage and damp problems. See cockroach control.

Bed bugs are year-round and, in a multi-unit building, always a neighboring-unit question from the first confirmed case. Inspecting above, below and either side is the difference between one treatment and six. See bed bug treatment.

Around those sit the seasonal work: pavement ants and odorous house ants in areaways, terraces and around moisture, spring through early autumn; carpenter ants where a failed cornice or flat sill has been wetting concealed timber; wasps and hornets at parapets, bulkheads and rear extensions in late summer; squirrels and occasionally raccoons at roof level near parks and mature street trees, where a licensed partner takes the animal out and the parapet, bulkhead and cornice closure is ours, under wildlife management; and mosquitoes as a source-reduction exercise in gardens, planters and roof drains.

What does the law require of a New York City building owner?

Four obligations that a board or managing agent should be able to describe from memory.

The Housing Maintenance Code places the duty to keep a dwelling free from rodents, insects and other pests on the owner, and requires extermination where an infestation is present. That duty does not turn on who reported the condition or how the building allocates cost internally. Full treatment at NYC Housing Maintenance Code — extermination and rodent eradication.

Local Law 55 of 2018, the Asthma Free Housing Act, converted a reactive duty into a scheduled one. Owners of multiple dwellings must investigate dwelling units and common areas at least annually and whenever a complaint arises, and must remediate using integrated pest management: physically removing pest nests and debris by HEPA vacuuming, sealing entry points so gaps are reduced to a quarter inch or less, and eliminating the water sources pests depend on. The law states plainly that pesticide use does not substitute for those measures, and that where pesticides are applied a licensed professional must do it. Full treatment at NYC Local Law 55.

The bedbug annual report is a separate filing made with HPD between 1 and 31 December each year by owners of multiple dwellings, including co-ops and condominiums, under Housing Maintenance Code sections 27-2018.1 and 27-2018.2. It reports the total number of dwelling units, the number infested, the number where eradication occurred and the number reinfested after treatment, aggregated for the whole building. The filing receipt must then either be given to occupants at lease commencement or renewal, or posted in a prominent public location.

Pesticide notification governs how and when residents are told before material is applied. See Local Law 36 pesticide notification for the city rule and the New York neighbor notification law for the state one, with New York State pesticide applicator requirements covering who may lawfully apply.

Boards and managing agents will also want co-op and condo board obligations; owners letting units, landlord and tenant pest responsibilities; and anyone comparing proposals, choosing a pest control contractor.

Which New York City markets do we serve?

Manhattan, Brooklyn and Queens, with fully researched pages for the three markets below and coverage across the rest.

Upper East Side — Manhattan’s most concentrated apartment-house market, where roughly 98 per cent of the housing sits in multi-unit buildings and five separate historic districts overlap townhouse blocks, pre-war co-ops, surviving Yorkville tenement rows and post-1955 towers.

Brooklyn Heights — over six hundred surviving pre-Civil War houses, about 78 per cent of the stock predating 1940, and a fabric that is almost entirely attached, so the party walls and the block interiors carry the work.

Park Slope — a hillside of subdivided rowhouses on the western flank of the Harbor Hill Moraine, draining toward the Gowanus lowland and its combined sewer overflows, with the city’s largest landmarked district by building count.

The wider service area covers Tribeca, SoHo, NoHo, Greenwich Village, Flatiron and NoMad, Hudson Yards, Central Park South and the Upper West Side in Manhattan; Williamsburg, Dumbo and Cobble Hill in Brooklyn; and Astoria, Whitestone and Malba in Queens. The complete list is on the service areas page.

How should a board or managing agent buy this work?

By buying coverage rather than frequency, and by refusing to compare proposals that are not describing the same scope.

The standard mistake is a contract priced on visits. A monthly service that treats whichever apartments called this month is a complaint-response arrangement wearing the clothes of a program. It produces a stable mid-level infestation — never reduced far enough to collapse, never given a closed route — and a file that shows a great deal of activity and no trend at all.

A program that changes the outcome has four parts. Monitoring runs building-wide instead of following the complaint log. It records what was found, where and when, in a form that is legible a year later. It corrects the structural and moisture conditions: chase penetrations, the compactor room, the failing refuse door, the broken drain line, the water at the base of the riser. And it uses material in the smallest quantity that does the job, applied by an appropriately certified applicator, as one component of the work rather than the whole of it.

Access is the part that most often derails it. Getting into every unit in a tenanted building takes notice, coordination and repeated attempts, and every attempt should be recorded — the notice sent, the window offered, the refusal, the re-attempt. An owner who tried repeatedly and was refused stands in a very different position from one who cannot show any attempt at all.

Sequence matters as much as scope. Reduce the existing population, correct the conditions, seal the routes, then verify. Sealing a building that still holds an active population removes the animals’ route out and concentrates them in the wall voids, which is worse than the situation you began with.

What can a resident actually do on their own?

A useful amount, and it is worth setting out honestly rather than pretending either that residents are powerless or that they can fix a building.

Seal what is inside your own walls. The openings around a supply line where it enters a wall, the gap behind a radiator riser, the unsealed penetration under a sink, the void behind a cabinet toe kick and the gap where a waste pipe passes through a floor are all inside your apartment and all yours to close. Packed mesh with a sealant over it holds; sealant alone does not, and cured foam is chewed straight through whatever it is sitting behind.

Fix the water. A dripping trap, a sweating cold line, a slow shower drain and a leaking radiator valve are the reasons a population chooses your apartment over the one next door. Insects need water more urgently than they need food, and removing it changes the local arithmetic quickly.

Report accurately and specifically. “There are roaches” produces a generic response. “Two adults and one nymph on the wall behind the sink, three nights running, always after midnight, worst in the corner nearest the stack” tells whoever comes where to look. Note dates, locations and what you actually saw rather than what you assume it was.

Do not treat around the edges of a building-wide problem. Over-the-counter material applied along a baseboard tends to disperse a population rather than reduce it, and repellent products in particular push animals deeper into the voids and along the chases into neighboring units. That makes the eventual professional work harder and slower.

Push for the building-level decisions. The compactor room, the chase penetrations, the cellar drain, the refuse storage and the coordinated inspection of a whole line are board and managing agent decisions. Residents who can describe the mechanism — that the chase is the route, and that per-apartment work relocates the problem — are considerably more persuasive at a board meeting than residents who can only describe their own inconvenience.

How does this compare with our Long Island work?

Same principle, entirely different surfaces — and it is worth understanding both if you own property in each.

On Long Island the building is a closed envelope with one owner. The pathways are the sill plate junction, the utility penetrations, the garage door corners, the soffit returns and the weep holes, and behind almost all of it is water arriving from a gutter, a grade or a flashing detail. The work is done from a ladder and a crawlspace, it is finite, and once it is done properly it holds for years without a schedule. The regional detail is set out on the Long Island hub, with market pages for Huntington, Great Neck, Manhasset, Port Washington and Garden City.

In the city the envelope is largely irrelevant to the problem in front of you, and the work is internal: chases, risers, joist pockets, refuse infrastructure and drainage. It is commissioned by a board or a managing agent rather than a resident, it involves access to other people’s homes, and it sits inside a statutory framework that has no equivalent for a detached house.

The one place the two converge is the multi-unit building on Long Island — a Great Neck Plaza co-op, a larger apartment building near a Manhasset or Port Washington commercial corridor. Those buildings follow city logic, not suburban logic, and the program for them is described under co-op and condo pest control and property management pest control.

When in the year does city work happen?

The urban calendar is flatter than the suburban one, but it is not featureless.

Late summer into autumn is the rodent window everywhere, and in the city it is when cellar, drainage and refuse work pays best. A building closed before the first cold nights does not take on a winter population.

Winter drives insects indoors and makes the vertical routes findable, because the heating is running and the warm columns are exactly the paths the animals prefer. Heat loss also becomes legible in January, and the places a building loses warmth are very often the places it admits animals.

Spring is the masonry season. A winter of freeze-thaw cycling records itself in spalled brownstone, open joints, failed sills and damaged cornices, and correcting those removes the moisture driving concealed insect activity later in the year.

Summer is for roof and exterior work — parapets, bulkheads, cornice returns and terraces — and for the source reduction that keeps mosquito pressure down in gardens and on roofs.

Regardless of season, evidence is worth acting on the week you see it. In a shared-riser building the interval between one apartment and four is measured in weeks, not seasons.

The reasoning behind this approach

Graduate Pest Control has been at work on buildings here and on Long Island since 1983. Arnold Katz founded it after studying entomology to degree level at the University of Georgia, and his son Ryan Katz has run it since. Ryan’s summary of the method runs to a single sentence: we treat every job as a building problem, not a pest problem. His second sentence is the one that filters inquiries — if you want someone to spray and leave, we are not the right fit.

In this city that position is arithmetic rather than attitude. A hundred households can be stacked above one cellar, one waste system, one bank of risers and one sewer connection, and the animals living among them are using that shared equipment rather than moving between homes. Money spent at the level of the building changes something permanent. Money spent at the level of the apartment buys a quiet fortnight, over and over, for as long as anyone is willing to keep paying for it.

If you would like a straight reading of what your building is doing and where its pathways run, get in touch. The pest control index lists the services in full, and commercial pest management covers boards, managing agents, restaurants, hotels and food facilities.