Bed Bug Treatment

In multi-unit buildings bed bugs move through shared walls, chases and conduit. Unit-by-unit treatment without a building plan fails.

What are bed bugs, and why is the problem so hard to end?

Cimex lectularius is a wingless, flattened insect that feeds exclusively on blood and spends the overwhelming majority of its life hidden within a few feet of where a person sleeps. An adult is roughly the size and color of an apple seed and becomes visibly engorged and elongated after feeding. It cannot fly and it cannot jump. Everything it does is walking, and everything it does at scale is being carried.

The difficulty is not that the insect is hard to kill. It is that the insect is hard to find and easy to move. A single mated female introduced into an apartment produces eggs over the following weeks, each nymph passes through five stages and requires a blood meal to complete each one, and every one of those stages is small, cryptic and thigmotactic — it wants to be wedged into a tight crack with surfaces touching it on both sides. By the time the population is large enough to be obvious, it is distributed across a dozen harborage sites in the room and, in a shared building, quite possibly beyond it.

That is what makes bed bug work different from most of what we do. It is not a chemistry problem. It is an inspection and logistics problem, and the buildings we work in — pre-war apartment houses in Manhattan and Brooklyn, walk-ups in Queens, multi-family conversions across Nassau and Suffolk — are exactly the building types where the logistics get complicated fastest.

How do bed bugs find a person in the dark?

By cues from the host, not by sight. A bed bug leaves harborage in response to a combination of signals: exhaled carbon dioxide, the thermal gradient from a warm body, and chemical cues from skin. The strongest of these at distance is carbon dioxide, which is why monitors designed for detection often use it, and why an unoccupied room does not draw them out in the same way.

Activity is concentrated in the hours before dawn in a typical household, aligning with the deepest period of a normal sleep cycle. That timing is behavioral rather than a strict light response: bed bugs feeding on a night-shift worker who sleeps in the day will shift accordingly. Anyone assuming they cannot have bed bugs because they leave a lamp on is relying on something that does not hold.

A feed takes minutes rather than seconds. The insect pierces the skin, injects saliva containing anticoagulant and anaesthetic compounds, feeds until engorged, then withdraws and returns to harborage to digest. It typically does not stay on the host. That is a meaningful difference from lice or fleas and has a practical consequence: bed bugs are transported in objects — bags, cases, clothing that has been set down, furniture — much more often than on the person.

Between meals the insect stays hidden, defecating in and around the harborage site. Those fecal deposits are the single most reliable field sign: dark, blackish spotting that has bled slightly into fabric or paper the way ink bleeds, along a seam, a crevice, a screw head or a joint. Cast skins from moulting nymphs accumulate in the same places, and heavy sites carry a distinctive sweetish, musty odor.

Why do bites vary so much between people?

Because the visible bite is not the injury. It is an allergic reaction to proteins in the insect’s saliva, and human immune responses to those proteins differ widely.

Some people develop itchy welts within hours. Others take several days, which destroys the intuitive assumption that a mark appearing on Tuesday reflects an exposure on Monday night. A significant proportion of people — and the proportion appears higher in older adults — show no visible reaction whatsoever despite being fed on regularly. Sensitivity also changes over time with repeated exposure, so a person who reacted mildly at first can begin reacting strongly weeks later, which is often misread as the infestation suddenly worsening when it may simply be the resident becoming sensitised.

The consequences of this are practical and they matter for boards and managing agents.

A resident reporting no bites is not evidence that a unit is clear. A resident reporting bites is not proof of bed bugs either, because a great many things produce itchy skin lesions and the pattern-based folklore — “three in a row” — is not diagnostic. We do not confirm an infestation from a description of skin marks. We confirm it from the insect, from cast skins, from eggs or from fecal spotting, and until one of those is found the job is inspection rather than treatment.

This is also why we ask about sleeping habits during an inspection rather than only about symptoms. A resident who has moved to the sofa because the bedroom is uncomfortable has usually moved a portion of the population with them, and the sofa is now the primary harborage.

How do infestations actually start, and why are they not a hygiene problem?

They start with an object arriving. The insect feeds on blood, so the resource that sustains it is the occupant. Cleanliness is irrelevant to whether a population can establish, which is why immaculate homes, new luxury buildings and high-end hotels get them at rates that surprise people who believe otherwise.

The realistic introduction routes are:

Travel. A case set on a luggage rack or a bed in an affected room, then opened at home. This is the most common route and the reason hotel and hospitality exposure has an outsized effect on residential caseloads.

Second-hand and discarded furniture. An item taken from a curb, bought used, or accepted as a hand-me-down. Discarded mattresses and upholstered furniture on a city sidewalk are frequently there precisely because they were infested.

Movement between units in a shared building. Discussed below, and the dominant route in multi-family housing once a building has activity anywhere in it.

Guests, carers, contractors and children’s belongings. Any bag that has spent a night somewhere with activity.

Moving and storage. Vans, boxes and storage units that have handled infested contents.

The stigma attached to bed bugs is the single biggest obstacle to resolving them in a building, and it is worth saying plainly to residents: this is not a reflection on your home. When people believe an infestation is a judgment on their housekeeping, they delay reporting, they attempt to handle it privately with retail products, and they sometimes move belongings into other rooms or other apartments. Every one of those responses spreads the problem and makes the eventual treatment larger. A board that treats reports as blameless and responds quickly has a materially smaller problem than one that does not.

Do-it-yourself efforts deserve a specific warning. Over-the-counter aerosols marketed for crawling insects are frequently repellent, and applying them to harborage sites scatters the population deeper into voids and into adjoining rooms. Several serious residential fires have resulted from people using flammable materials against bed bugs. If you think you have them, the correct first action is to stop, not to spray.

Where do bed bugs harbor, and how do we find them?

Within a few feet of where the host rests, in cracks and crevices where the insect can be in contact with a surface on more than one side.

An inspection works outward from the sleeping surface in a defined order.

The bed. Mattress seams, piping and tags. The box spring, and particularly its underside — the stapled dust cover on a box spring is a classic harborage and has to be lifted or removed to inspect properly. Bed frame joints, bolt holes, and the recesses in a metal frame. Headboards, especially the back face and any wall-mounted headboard, which in hotels is one of the highest-yield inspection points in the room.

Immediately adjacent. Nightstands, including drawer runners and the underside. The seam where carpet meets the wall, and the tack strip behind it. Baseboard joints. Outlet and switch plates. Curtain hems and rod ends. Picture frames and anything hanging near the bed.

Seating. Sofa and armchair seams, under cushions, in the recess of the frame, and inside recliner mechanisms.

Further out, in established infestations. Behind loose wallpaper, in the joints of built-in cabinetry, in books, in cluttered storage, in the folds of curtains, and inside small appliances and electronics near the bed.

Method matters more than equipment. A proper visual inspection is slow, uses a bright flashlight held at a low angle so that spotting and cast skins stand out against fabric, and involves physically taking things apart — lifting dust covers, removing outlet plates where circumstances allow, turning a bed frame over. A crevice tool and a card to run along a seam are more useful than anything expensive.

Interceptors placed under the legs of beds and seating are one of the most useful low-cost tools available. They trap insects moving to and from the host, they cost little, and they give you evidence over time rather than a snapshot. In a building with a history, standing interceptors in units adjacent to a confirmed case are a rational monitoring measure.

Canine detection is used in this industry for exactly this problem, because the limiting factor is finding low-level activity in many units. We would rather describe what a specific detection program covers when we scope your building than make general claims about it here.

How do bed bugs move through an apartment building?

Through the building’s own voids. This is the point at which a bed bug problem stops being a household matter and becomes a structural one.

Adjoining apartments are separated by assemblies that are continuous in more places than they look. Plumbing chases run vertically behind stacked kitchens and bathrooms. Electrical conduit and boxes penetrate walls, and back-to-back outlet boxes in a shared wall are a direct passage between two units. Radiator and riser penetrations through floors are frequently open annuli. Party walls in attached houses and brownstones have joist pockets. Dropped ceilings create horizontal voids that run past unit boundaries. Baseboard and floor perimeters, where the finish flooring stops short of the framing, provide a continuous edge route.

Bed bugs use all of it, and their preference for tight, contact-rich spaces makes conduit and voids congenial rather than difficult. Movement is generally short-range and slow compared with the speed at which people carry them, but over weeks it is enough to establish a population in a neighboring unit. Displacement also accelerates it: an aggressive or badly executed treatment in one apartment pushes surviving insects along those same routes, which is one of the mechanisms by which a building’s problem gets worse immediately after a resident treats their own unit.

There is a further pathway that is purely human. Shared laundry rooms, refuse rooms, elevators, hallway carpeting and communal seating all handle infested items. A resident carrying a bag of bedding to the basement laundry can seed a route used by everyone in the line.

The structural half of the response is the same discipline described under structural exclusion: sealing pipe penetrations at every floor, closing gaps at outlet and switch boxes, sealing baseboard and floor perimeter gaps in affected units, and closing chases. It does not eliminate a population by itself and it is not a substitute for treatment. What it does is stop the building from redistributing the problem faster than the treatment resolves it.

What treatment approaches exist, and how do they differ?

There are several, they have genuinely different profiles, and the right answer depends on the room, the contents, the occupants and whether the building has activity elsewhere.

Conventional application. Materials applied precisely to harborage sites, cracks, crevices, voids and the framework of furniture, in accordance with the product label and applicable regulation. Applied well, this leaves residual activity where the insects travel, which is important in a building where reintroduction is likely. Applied badly — broadcast over surfaces rather than placed into harborage — it achieves very little and can disperse the population. Resistance to certain classes of insecticide is documented in bed bug populations, which is why relying on one mode of action indefinitely is a poor strategy and why results are monitored rather than assumed.

Heat. The room or the contents are brought to a lethal temperature and held there for a sustained period, using equipment that circulates air so the target temperature is reached in voids and inside contents rather than only at the thermostat. Its advantages are real: it kills every life stage including eggs, and it treats contents that are hard to treat any other way. Its limits are equally real. Heat has no residual effect at all, so an insect walking in from next door the following week is unaffected. Deep voids, dense stacks of belongings and exterior walls in winter can shelter insects below lethal temperature. Heat-sensitive items must be removed. And it requires substantial power and equipment access, which is not always available in an older building.

Steam. Directed steam kills on contact, including eggs, and is very useful on mattress seams, upholstery, carpet edges and furniture joints where a residual application is undesirable. It is slow, and it is precise work rather than a room-scale treatment.

Vacuuming. Mechanical removal of insects, cast skins and eggs from accessible harborage. It reduces the population immediately, it improves the appearance and habitability of the room, and the contents of the vacuum are removed from the building rather than left in place.

Encasements. After treatment, sealing the mattress and box spring in a purpose-made encasement isolates anything remaining inside and turns a complicated inspection surface into a smooth one. This has ongoing value: for the life of the encasement, checking the bed is a two-minute job.

Non-chemical support measures. Laundering and high-heat drying of textiles, isolating treated items, and interceptors under furniture legs.

In practice most jobs use a combination. What we will not do is name products or discuss dosing on a public page — that is label-governed, situation-specific and not something to decide from a website.

How should a room be prepared?

Preparation is genuinely part of the treatment rather than an administrative inconvenience, and under-preparation is one of the most common reasons a treatment underperforms.

The general shape of it: launder and high-heat dry all bedding, clothing from affected rooms and soft furnishings that can take it, then bag the clean items and keep them isolated until the work is finished. Empty nightstands and dressers in the affected rooms so their surfaces and voids can be reached. Reduce clutter, particularly stored cardboard, because every box is a harborage and an inspection obstruction. Leave furniture in place unless you are told otherwise, and above all do not move mattresses, upholstered furniture or bagged belongings into another room, another apartment or a hallway.

Preparation requirements vary a great deal by method — a heat treatment has specific requirements around heat-sensitive and pressurised items that a conventional treatment does not — so the specific list comes from us for your specific job. Where residents are elderly, have mobility limitations or have hoarding conditions, the preparation itself often needs support, and a building that ignores that reality ends up with untreatable units that keep reseeding the rest of the line. It is worth planning for.

Why does treating one apartment at a time fail?

Because the treatment boundary and the infestation boundary are different shapes, and in a shared building the infestation is the larger of the two.

Consider a building with confirmed activity in one apartment. If only that apartment is treated, three things are simultaneously true. Insects may already have moved into the adjoining and vertically adjacent units, where nothing is being done. The treatment itself may drive survivors along the same pathways. And the treated unit remains open to reintroduction from those neighbors as soon as the residual effect wanes. The building then experiences a rolling pattern of complaints across a line of apartments over many months, each treated in isolation, none of them ever resolving. This is not hypothetical; it is the normal failure mode.

A building-scale approach looks different. It inspects the confirmed unit and a defined ring around it — at minimum the units sharing walls, the unit above and the unit below — regardless of whether those residents have reported anything, because a substantial proportion of people do not react to bites. It treats what is found, monitors what is not, seals the structural pathways between them, and repeats the inspection on a schedule until the monitoring is clean. It also handles the human logistics: notice to residents, access, preparation support, and a record of what was done in each unit and when.

That record is not bureaucracy. Owners of multiple dwellings in New York City carry obligations relating to bed bugs, including disclosure requirements to prospective tenants regarding a building’s recent bed bug history, and any board or agent will at some point need to demonstrate what was inspected, what was found and what was done. The way to have that documentation is to have run the program properly in the first place. We work with boards and managing agents on exactly this basis, and the broader version of it sits under our commercial work.

How is the work verified?

By evidence gathered over weeks, not by the absence of complaints after a fortnight.

The reason is biological. Eggs present at the time of treatment may not all be affected by every method, and nymphs emerging afterwards take time to grow to a stage that is easily seen or that produces a reaction in the occupant. A room can look and feel resolved and then produce activity a month later. So the follow-up runs on a schedule: repeat inspection, interceptors left in place and checked, monitors in harborage areas, and a further treatment where anything is found.

We would rather set the expectation honestly at the start. A straightforward single-family bed bug job is usually a matter of a small number of visits over several weeks. A building-wide program in a multi-unit property is a program, with a defined inspection ring, a schedule and a closing criterion. Anyone offering a single visit and a clean bill of health on the same day is selling something that the insect’s life cycle does not support.

What is at stake for hotels and hospitality operators?

More than the treatment cost, and the difference is mostly about response rather than incidence.

A hotel with turnover in the hundreds of guests per week is exposed continuously. Introduction is not a sign of failure; it is an inevitability that has to be managed. What separates a well-run property from an exposed one is the process around it: housekeeping trained to recognize fecal spotting on a mattress seam and on the back of a headboard, a reporting route that does not require a housekeeper to risk being blamed, a defined protocol that takes a reported room out of service immediately, an inspection ring covering adjoining and vertically adjacent rooms, and a written record of every report and every response.

The liability exposure sits almost entirely in the gap between a guest’s report and the operator’s action. A property that inspected, documented and acted within hours is in a very different position from one where a complaint was logged, the room was turned and re-let, and a second guest reported the same thing a week later. Brand standard audits look at the same thing. So do insurers.

The same logic applies to residential managing agents with portfolios, to student and staff housing, and to any operator with rooms that change occupants frequently. If that describes your operation, the commercial pages set out how we structure the program.

Related work

Bed bugs share their pathways with other multi-unit pests, so the work overlaps. The chases, conduit and joist pockets that carry them between apartments are the same routes used by cockroaches and by mice and rats, and a building serious about one of these problems usually finds the survey answers questions about the others. The physical closing of those pathways is described under structural exclusion.

The building-wide version of this argument, including how far an inspection should reach and who actually commissions the sealing work, is written up in the shared walls cluster on our blog.

Everything we cover is listed on the pest control services page, the areas of New York City and Long Island we serve are on the locations page, and if you have a confirmed or suspected case the practical next step is to contact us with the building type, the number of units involved and what has been seen.