Stink bugs are a fall problem you solve in early fall, not in January.
Brown marmorated stink bugs don't breed indoors and they don't damage your house. They come in to overwinter, gathering on warm sunny walls in September and October and slipping through gaps around windows, siding, soffits, and attic vents. Once they're in the wall voids, options narrow considerably. The entire game is timing and exclusion.
What to watch for
Stink bug activity follows a predictable seasonal pattern on the North Shore.
- Clustering on sunny exterior wallsWarm September and October afternoons bring large aggregations to south- and west-facing siding. This is the window where exterior treatment is effective — before they get in.
- Bugs appearing indoors on warm winter daysA mild spell in January or February warms wall voids and wakes overwintering adults, which then move toward light and turn up on windowsills and ceilings.
- Concentration in attics and upper floorsThey move upward and toward warmth. Attic spaces, second-floor windows, and recessed lighting fixtures are common gathering points.
- The odor when disturbedA distinctive cilantro-like smell released when they're crushed or threatened. It's the reason not to vacuum them with a household vacuum — the odor lingers in the bag and the machine.
- Entry around window frames and siding gapsBehind shutters, under siding laps, around window and door frames, and at any unsealed utility penetration. Their flattened shape lets them use remarkably small openings.
- Attic vents and soffit gapsUnscreened gable vents, ridge vents, and soffit gaps are the most common bulk entry points and the most worthwhile to seal.
How we approach stink bugs
- Exterior inspection for entry pointsWe survey siding laps, window and door frames, utility penetrations, soffit and gable vents, and any gap wide enough to admit a flattened insect.
- Seal and screenCaulking gaps, repairing damaged screening, and adding hardware cloth to vents. This is permanent work that also keeps out cluster flies, boxelder bugs, and ladybird beetles, which follow the same seasonal pattern.
- Time the exterior applicationA perimeter application to sunny walls, eaves, and around openings, applied in early fall as aggregations form. Timing is everything — the same treatment in November accomplishes very little.
- Handle what's already insidePhysical removal, and treatment of accessible voids where warranted. We're candid about the limits here: once they're overwintering in a wall cavity, exclusion for next year is often the honest answer.
- Set up for next seasonWe note which walls and openings drew activity so the following year's service is targeted rather than general.
Why we don't treat wall voids full of stink bugs
It's a reasonable question — if they're in the wall, why not treat the wall? Because killing a large number of insects inside an inaccessible cavity leaves a large number of carcasses there, and those attract dermestid beetles and carpet beetles, which then move into the living space and feed on wool, stored fabrics, and pantry goods. You trade a seasonal nuisance for a permanent one. Exclusion before they enter is genuinely the better approach, not a way of avoiding the work.
Don't use your household vacuum
The defensive compound is persistent and it will make a vacuum smell for months. If you're removing them yourself, a shop vac with a disposable bag you can seal and discard outside works well, or simply a jar of soapy water. Some homeowners keep an old vacuum designated for the purpose during the fall and winter.
They're a nuisance, not a threat
Brown marmorated stink bugs don't bite, don't sting, don't reproduce indoors, and don't damage structures or stored food. They're an agricultural pest of real consequence — orchards and vegetable growers take them seriously — but inside a house they're strictly a nuisance. That's worth knowing when you find forty of them on a windowsill in February.
Where we provide this service
Northport, East Northport, Huntington, Halesite, Centerport, Greenlawn, Cold Spring Harbor, Fort Salonga, and the surrounding North Shore communities. See all service areas.
Not sure what you're dealing with?
Send a photo by text and we'll tell you what it is. Identification is free, and it's the step that determines everything else.