Stink Bugs in the Hudson Valley: Why They Invade Every Fall and How to Keep Them Out
Brown marmorated stink bugs swarm Hudson Valley homes every September and October. Here's the timing, the entry points, and the fix.
Why your house, and why now
Brown marmorated stink bugs don't want your food — they want your warmth. As nights drop into the 50s in September, they gather on sunny south- and west-facing walls, then slip into wall voids and attics to overwinter. A home that had them last year will attract them again: they leave aggregation pheromones that call in the next generation.
The entry points that matter
Window and door frames, soffit and ridge vents, gaps around air conditioning lines, attic vents, and worn weatherstripping. They flatten their bodies to fit through gaps under 1/8 inch — far smaller than most homeowners expect.
The two-week window that decides your winter
Exclusion and exterior treatment have to happen before the swarm, not after. In the Hudson Valley that means late August through mid-September. Once hundreds are inside the walls, you're managing them all winter — vacuuming, not preventing.
What to do with the ones already inside
Vacuum them (use a shop vac or a bag you'll seal immediately — the smell lingers in a regular vacuum). Don't crush them. A soapy-water trap under a desk lamp overnight catches stragglers. Skip indoor pesticide sprays — they don't reach the wall voids where the bugs hide.
The professional difference
A fall exterior treatment applies a residual barrier to siding, eaves, and entry points during the aggregation window, plus sealing of the accessible gaps. Done in time, it stops the invasion instead of chasing it.