Pest Library
Stink Bugs
Brown marmorated stink bugs gather on warm walls each fall.
Overview
The brown marmorated stink bug is an invasive shield-shaped insect that gathers on sun-warmed exterior walls in early fall, then works its way into attics, wall voids and window frames to overwinter. It does not bite, breed indoors or damage structures.
They reappear indoors on warm winter days and again in spring as they try to get back outside — which is when most homeowners notice them on windows and ceilings.
What to look for
Identify the pest
Compare what you found with these stink bugs reference materials.
Brown marmorated stink bug
Shield-shaped brown bug with alternating light bands on the antennae and abdomen edge.
Adult close-up
Banded antennae are the most reliable feature separating it from native stink bugs.
Signs of activity
Most homeowners find the evidence before they find the pest. These are the things people usually notice first.
Around windows
Indoors they gather on window glass and frames as they look for light.
Clusters on siding
On warm fall afternoons they gather on sunny south- and west-facing walls before moving in.
Photos can help narrow down a pest problem, but many pests and signs of activity look similar. A photograph should not be treated as a definitive identification or diagnosis. Photo sources and credits.
Does this look familiar?
Pest signs aren't always easy to identify from pictures. Send us a photo of what you're seeing and tell us where you found it — we'll take stink bugs into account.
Why they're common in the Hudson Valley
- The species is well established across the Hudson Valley and the mid-Atlantic.
- Homes with large south- and west-facing walls, and properties near orchards, gardens and tree lines, tend to see the heaviest fall gatherings.
- Older windows, attic vents and gaps behind trim provide easy entry.
Signs of activity
- Clusters on siding, especially sunny sides of the house, in September and October
- Bugs on window glass, curtains and ceiling corners indoors
- A pungent odor when they are crushed or vacuumed
- Activity returning during warm winter spells
Where you'll find them
- Attics and upper-floor window frames
- Behind exterior trim, shutters and siding
- Soffit and gable vents
- Sunny south- and west-facing exterior walls
Why it matters
- They are a nuisance rather than a health or structural threat.
- Crushing or vacuuming releases their odor; a dedicated shop vac or soapy water works better.
- Large numbers indoors indicate exterior gaps that other pests can also use.
Prevention
- Seal gaps around windows, doors, trim and utility penetrations before September
- Repair or screen attic, soffit and gable vents
- Add or replace worn weatherstripping and door sweeps
- Use a vacuum with a disposable bag or drop them into soapy water
- Address exterior gaps in late summer, before the fall gathering begins
When to get an inspection
- You get large numbers indoors every fall and spring
- You want help identifying and sealing entry points
- You are also seeing other overwintering pests such as cluster flies or ladybugs
- Exterior treatment timing before the fall gathering would help
Stink bugs showing up inside?
If the activity keeps coming back, an on-site inspection is the reliable next step.