Why Ants Show Up in NYC Apartments Every Spring
Ant colonies don't disappear in winter — they go dormant, moving deeper underground or into wall voids to survive the cold. Once temperatures climb above roughly 50°F and stay there, forager ants begin exploring for food and moisture. In NYC, where buildings sit directly on top of each other and gaps around pipes and conduits run between units, those foragers tend to end up in apartments.
The timing this spring has been especially sharp. After a cold winter that stretched into early spring, temperatures across New York climbed sharply through April, accelerating colony wake-up cycles. If you started seeing ants in late April, you're not imagining it — the spring emergence arrived earlier than usual this year.
NYC apartments have structural features that make ant entry almost unavoidable without intervention: gaps around water pipes under kitchen sinks, worn weatherstripping on exterior doors, and cracks in the building envelope where ants can slip through at any floor level, not just the ground floor.
The Three Ant Species You're Most Likely Seeing
Pavement ants are the most common culprit in NYC apartments. Small — 1/16 to 1/8 inch — and dark brown to black, they build colonies under sidewalks and building foundations and forage upward through any available gap. You'll often spot a trail running from a baseboard crack toward the kitchen.
Odorous house ants look similar to pavement ants but have a telltale smell — crushed, they release a rotten-coconut odor. They're aggressive foragers in kitchens and bathrooms and love moisture as much as food, which makes a dripping pipe under the sink a prime attractant.
Carpenter ants are the ones worth taking seriously. Much larger — up to 1/2 inch — and black or dark red, they don't eat wood the way termites do, but they excavate galleries in damaged or moist wood to nest. Seeing carpenter ants consistently inside your apartment, especially near bathroom fixtures or window frames, can signal an existing moisture problem or wood damage in the structure.
What You Can Do Right Now
Cut off food and moisture. Ants follow trails to food and water. Wipe down counters after cooking, store food in sealed containers, take out the trash regularly, and fix any dripping faucets or slow leaks under the sink. These steps won't eliminate an active colony, but they remove the reason forager ants keep returning to your unit.
Find and seal entry points. Follow ant trails back to where they're entering. Common points in NYC apartments: gaps around water supply and drain pipes under the kitchen or bathroom sink, gaps along the baseboard near an exterior wall, and the opening around the cable or internet conduit where it enters the unit. Use caulk for small cracks. For larger structural gaps, report them to your super — sealing those properly is the building's responsibility.
Use bait, not spray. This is the most common DIY mistake. Spraying the ants you can see kills foragers but leaves the colony intact, and new foragers show up within days. Ant bait — gel bait or slow-acting bait stations — works because foragers carry it back to the queen. Place bait near active trails, keep it away from spray products, and give it at least one to two weeks to work. Don't clean the trail during that time; the trail is how foragers find the bait in the first place.
When to Involve Your Landlord
Under the NYC Housing Maintenance Code, landlords are required to keep apartments free from pest infestations and to address the underlying conditions that allow infestations to persist — including sealing structural gaps, repairing moisture damage, and scheduling professional extermination when a tenant reports a problem in writing.
If ants keep coming back after you've done everything on your end, and you've traced the entry to a structural gap you can't access, put your complaint in writing to your landlord or super. Email works. A 311 complaint creates a timestamped record if you need to escalate. If the landlord fails to act, tenants can file a complaint through the NYC Department of Housing Preservation and Development (HPD).
If ants are appearing in multiple units at the same time, that's a building-wide problem requiring coordinated treatment — not unit-by-unit spraying. A single treated apartment won't solve anything if the colony is nesting in the building's structure. Coordinate with neighbors and file a building-wide complaint if that's what you're up against.
For a full rundown of your rights when your landlord isn't responding to pest complaints, see our guide on NYC tenant rights for pest control.
When Professional Treatment Makes Sense
Pavement ant trails that reappear after two full weeks of bait treatment — or any carpenter ant activity near wood framing — are signs that a professional inspection is warranted. A licensed exterminator can locate the colony, apply treatment in wall voids and pipe chases that aren't reachable with off-the-shelf products, and identify the structural conditions allowing re-entry.
Carpenter ants in particular deserve professional follow-up. The goal isn't just eliminating the insects — it's identifying and addressing the moisture source that attracted them. If you're seeing large black ants consistently every spring in the same spots, that pattern is evidence of an ongoing structural issue worth catching before it becomes a larger repair problem.
Ant pressure also varies by building type and location. Ground-floor and garden-level apartments in Brooklyn brownstones and Queens attached row houses typically see heavier pavement ant pressure than upper-floor units in Manhattan high-rises, though no building is genuinely immune when colony populations are high.
For a month-by-month breakdown of which pests to expect throughout the year in NYC, our NYC seasonal pest calendar covers all five boroughs.
Ready to Get the Ants Under Control?
If ants have been trailing through your apartment for more than a week and bait isn't making a dent — or if you've spotted what looks like carpenter ants anywhere near wood — call for a professional assessment. Reach us at (855) 930-5016. We can identify the species, pinpoint where they're entering, and recommend the right treatment for your specific apartment situation.