The fastest way to get rid of stink bugs already inside your home is to vacuum them up or drop them into a container of soapy water. But the real fix is sealing them out before they arrive. Brown marmorated stink bugs move toward buildings on warm, sunny days in September and October, squeezing through surprisingly small gaps to hibernate in your walls, attic, and ceiling voids. A combination of exclusion, removal, and outdoor management will keep their numbers low year after year.
Why They’re in Your House
Stink bugs aren’t breeding indoors or feeding on anything in your home. They’re looking for a cool, dry place to spend the winter, and the cracks and voids inside walls and attics mimic the rocky outcroppings and loose bark they’d naturally choose. They favor upper areas of buildings, often entering through attics and chimneys, and they’re drawn to sun-warmed surfaces in the afternoon. Flight activity peaks on clear fall days and can vary dramatically from one day to the next, which is why you’ll sometimes see dozens one afternoon and none the next.
By late fall, the bugs settle into hibernation. Then from March through May, they wake up and try to get back outside. That’s when they sometimes wander into living spaces instead, appearing on walls or near windows as temperatures rise. They aren’t invading again. They’re the same bugs from fall, disoriented and heading the wrong direction.
Seal Entry Points Before Fall
Exclusion is the single most effective strategy. Research from Virginia Tech and the USDA found that slits narrower than 3 millimeters and holes smaller than 7 millimeters successfully block nearly all adult stink bugs. In testing, only one bug managed to squeeze through a 7-millimeter hole, and none passed through a 3-millimeter slit. That means even small gaps around your home are worth addressing.
Common entry points include gaps around windows, doors, roof flashing, soffits, fascia boards, vents, pipes, and wires. Window-mounted air conditioners are another frequent culprit and should be sealed or removed before fall. Focus on these areas:
- Windows and doors: Apply caulk to any visible cracks in the frames. Replace worn weatherstripping so doors close tightly.
- Attic and soffit vents: Install fine screening behind vents. Choose a mesh small enough to block entry (openings under 7 mm) but not so fine that it restricts airflow if your ventilation is near its design minimum.
- Window screens: Repair any tears or holes. Stink bugs don’t need much space to get through.
- Chimneys and roof gaps: Check flashing and chimney caps for gaps. Stink bugs tend to enter from high points on a building.
The ideal time for this work is late summer, before the bugs start scouting buildings in September. Once they’ve already settled into wall voids and attic spaces, sealing won’t help with the current population and can actually trap them inside, increasing the chance they’ll emerge into your living areas in spring.
Removing Stink Bugs Indoors
Don’t crush them. Stink bugs release a sharp, unpleasant odor when disturbed or squished. The smell lingers and can stain surfaces. The defensive spray is not the same chemical as their aggregation pheromone (the scent that draws other stink bugs to an area), so crushing one won’t technically “call” more bugs. But it will make your house smell terrible.
A vacuum cleaner is the most practical tool for removing them in bulk. Use a shop vac or a vacuum with a bag you can immediately seal and throw away. If you use a bagless vacuum, the odor can linger inside the canister. Some people dedicate a cheap handheld vacuum solely to stink bug duty.
For smaller numbers, the soapy water method works well. Fill a jar or bucket with water and add 1 to 2 teaspoons of dish soap per pint. The soap breaks the surface tension of the water, so bugs sink and drown instead of floating on top. Flick or knock the bug off the wall directly into the container. This is quiet, odor-free, and effective.
Why Indoor Pesticides Don’t Work
The National Pesticide Information Center is blunt on this point: using pesticides inside the home to control stink bugs is often ineffective. The bugs are hiding deep in wall voids and attic spaces where sprays can’t reach them. By the time you see one walking across a wall, it’s already left its hiding spot, and killing it with a spray is no more efficient than vacuuming it. If you do choose any indoor product, opt for lower-toxicity options first and always read the label before buying.
DIY Light Traps
Stink bugs are attracted to light, which is why they often cluster near windows and lamps. You can exploit this with a simple homemade trap: place a desk lamp over a shallow pan of soapy water in a dark room. The bugs fly toward the light, land in the water, and drown. This works best at night in rooms where you’ve noticed activity, like attics or spare bedrooms. It won’t eliminate a large infestation, but it steadily reduces numbers over days and weeks without any chemicals or odor.
Outdoor and Perimeter Control
Treating the exterior of your home in early fall, before bugs begin migrating, is more effective than any indoor approach. Residual insecticide sprays containing pyrethroids can be applied around window frames, door frames, soffits, and other entry points. The goal is to create a barrier that kills or repels bugs as they land on the building. Timing matters: apply before the main migration period, typically early to mid-September depending on your region, and reapply if heavy rain washes the product away.
For professional-level infestations, particularly on homes surrounded by agricultural land or wooded areas, a pest control company can apply longer-lasting perimeter treatments and identify entry points you might miss.
Protecting Your Garden
Stink bugs feed by piercing plant tissue and sucking out fluids, which makes them particularly damaging to developing fruits, beans, nuts, and seeds. You’ll often notice dimpled, discolored spots on tomatoes, peppers, and other crops where they’ve fed.
Row covers are one of the most effective physical barriers for vegetable gardens. Lightweight fabric draped over hoops keeps stink bugs off plants entirely while still allowing light and water through. This avoids chemicals altogether and works well for smaller garden beds.
Hand-picking is tedious but effective for manageable populations. Check the undersides of leaves for clusters of barrel-shaped eggs and destroy them. Young nymphs tend to feed in groups near where they hatched, so catching them early prevents a generation of damage. Drop any bugs or egg masses into soapy water.
Keeping weeds controlled around your garden helps prevent heavy infestations, since stink bugs use weedy borders as habitat. Creating a welcoming environment for beneficial insects also helps. Pill bugs, among other predators, eat stink bug eggs. Avoiding broad-spectrum pesticides in your yard preserves these natural allies.
If you need a garden spray, contact-based products like capsaicin (hot pepper wax) sprays or permethrin dusts must coat the bugs directly to work. They don’t have residual action against stink bugs hiding on the undersides of leaves, so thorough coverage and repeat applications are necessary. Systemic pesticides, which are absorbed into plant tissues, should not be used on any fruits or vegetables you plan to eat.
What Doesn’t Work
Stink bugs don’t overwinter in mulch, leaf litter, or shrubs. These spots are too damp for their survival. So raking leaves or replacing mulch near your foundation won’t reduce their numbers. They also aren’t attracted to food in your kitchen or pantry, so cleaning won’t deter them the way it would with ants or roaches. Their presence is purely about shelter, not food.
Ultrasonic repellers, essential oils, and dryer sheets are frequently recommended online, but none have reliable evidence behind them. Your effort is better spent on physical exclusion and direct removal, the two approaches that consistently reduce indoor stink bug numbers season after season.