The Order Matters
Almost every disappointing stink bug season comes from doing these two jobs in the wrong order, or doing only the second one.
- Exclusion decides how many get in. It is done on the outside of the building, ideally before September, and it is the only thing that changes next year’s number.
- Removal deals with the ones already inside. It is done indoors, it is endless while they keep arriving, and it changes nothing about next year.
The reassuring part, covered on the identification page, is that removal is a finite job. University of Kentucky Extension states the adults overwinter in an unmated condition and do not breed or reproduce indoors, so the population in your walls is whatever came in and no more.
Step One: Seal
University of Kentucky Extension’s advice is to seal cracks around windows, doors, soffits, fascia boards, pipes and wires with caulk. Penn State Extension gives the same instruction and specifies good quality silicone or silicone-latex caulk, adding that damaged screens on doors and windows should be repaired or replaced.
Mesh size is the detail people get wrong. University of Kentucky Extension specifies screening with a mesh size no larger than 1/6 inch for attic and exhaust vents, and warns that conventional galvanized hardware cloth is not effective because its openings are too large. Penn State Extension gives number 20 mesh or smaller for the equivalent job. A vent you already screened may not be screened finely enough.
Timing matters as much as technique. Kentucky Extension gives early-to-mid September as the point at which the insects start arriving in that state. Sealing in November is sealing them in.
Where to Seal
Work from the top down, because that is where they are. University of Kentucky Extension notes they gather on windows, doors, roof flashing, vents, fascia and siding, and prefer the upper areas of buildings.
- Attic and gable vents — the mesh question above.
- Soffits and fascia boards — gaps where the roof meets the wall.
- Roof flashing — around chimneys and where rooflines meet.
- Window and door frames — including the gap behind trim.
- Utility penetrations — pipes, wires, cable and dryer vents.
- Siding — loose or lifted sections, and the gap at the top course.
- Exhaust fan and light housings in ceilings — these open into the attic.
Virginia Tech’s Thomas Kuhar puts the whole exercise in one sentence: make sure your house is well sealed and close off entryways to help reduce the number of stink bugs in your home, and do not leave windows open without a screen.
Step Two: Vacuum
For the ones already inside, a vacuum is the standard advice. Penn State Extension says they can be removed from interior areas with the aid of a vacuum cleaner, with one warning attached: the vacuum may acquire the smell of stink bugs for a period of time.
That warning is the whole reason vacuum choice matters, and there are two workable approaches.
- A bagged vacuum, or one you have dedicated to the job. University of Kentucky Extension notes that a large collection may warrant disposing of the entire vacuum bag and airing out the hose. That is easy with a bag and unpleasant without one. Penn State Extension’s lady beetle guidance is to remove the bag after each session and either tape and discard it or freeze it.
- The nylon stocking method, which works in any machine. University of Kentucky Extension describes putting a cut-off nylon stocking in the suction tube to limit odor. Penn State Extension gives the same technique for bagless vacuums: place a nylon stocking into the hose and secure it with a rubber band. The insects collect in the stocking, you tie it off and remove it, and nothing ever reaches the canister.
One more mechanical note, from Ohio State University Extension’s guidance on the lady beetles that arrive in the same weeks: use a fan-bypass vacuum rather than a direct-fan model. In a direct-fan machine the insects pass through the impeller, which crushes them — and crushing is exactly what releases the odor.
The Bottle Trick
Virginia Tech’s Thomas Kuhar offers a zero-cost alternative for catching them off a wall or ceiling without touching them: cut the top off a two-liter bottle, flip it over, and put it back on the bottle. That gives you a funnel that they drop into and cannot easily climb out of.
It is slower than a vacuum and better for the one bug on the lampshade at eleven at night than for forty on an attic window.
What Not to Do
- Do not squash them. University of Kentucky Extension notes the odor is released when they are crushed, squeezed or handled, and advises against touching your face or eyes afterward.
- Do not use insecticide indoors. Penn State Extension states it is not advisable to use an insecticide inside after the insects have gained access. University of Kentucky Extension says insecticides are not warranted indoors except perhaps in heavily infested areas such as attics, and that treating wall cavities is unlikely to be successful and could exacerbate problems with carpet beetles. The failure mode is specific: dead insects in a void feed a pest that does eat fabric.
- Do not seal after they are in. You will trap them in the wall, where they will emerge indoors on warm days all winter.
- Do not treat this as a hygiene problem. Nothing indoors attracted them and nothing you clean will discourage them.
When It Is a Professional Job
University of Kentucky Extension notes that many companies apply insecticides to building exteriors in the fall, as a targeted band around windows, doors and eaves, with timing given as early-to-mid September in the Midwest.
We make no claim on this page about how well any product performs. What the sourced material does support is that the timing is the constraint: an exterior treatment has to be in place before the insects arrive, which in practice means booking it in late summer rather than in October when the problem becomes obvious.
The other honest reason to call someone is height. Most of the gaps that matter are at roofline, and the reason people do not seal them is that they are three stories up.
Questions
What actually gets rid of stink bugs?
Sealing the building, and then removing the ones already inside by hand or by vacuum. University of Kentucky Extension describes mechanical exclusion as the approach: seal cracks around windows, doors, soffits, fascia boards, pipes and wires with caulk. Nothing you do indoors reduces next year’s number; only closing the openings does that.
What screen mesh size keeps stink bugs out of attic vents?
University of Kentucky Extension specifies screening with a mesh size no larger than 1/6 inch for attic and exhaust vents, and notes that conventional galvanized hardware cloth is not effective because the openings are too large. Penn State Extension gives number 20 mesh or smaller for the same job on lady beetle exclusion, which is a comparable specification.
Is it safe to vacuum stink bugs?
Yes, and it is the usual advice, with one caveat. Penn State Extension notes that the vacuum may acquire the smell of stink bugs for a period of time. University of Kentucky Extension suggests putting a cut-off nylon stocking in the suction tube to limit odor, and says a large collection may warrant disposing of the entire vacuum bag and airing out the hose.
Should I use a bagged vacuum or a bagless one?
Either works if you plan for the odor. With a bagged vacuum you can seal and discard the bag. With a bagless machine the smell has nowhere to go, so the nylon-stocking method University of Kentucky Extension describes is more useful: the stocking traps the insects, you tie it off and remove it, and nothing reaches the canister. Penn State Extension gives the same stocking technique for lady beetles.
Why should I not spray insecticide inside for stink bugs?
Penn State Extension states that it is not advisable to use an insecticide inside after the insects have gained access. University of Kentucky Extension adds that insecticides are not warranted for controlling stink bugs indoors, except perhaps in heavily infested areas such as attics, and that treating wall cavities is unlikely to be successful and could make carpet beetle problems worse. Dead insects in a void become food for something that does damage fabric.
Do exterior insecticide treatments work?
University of Kentucky Extension notes that many companies apply insecticides to building exteriors in the fall, as a targeted band around windows, doors and eaves, with timing given as early-to-mid September in the Midwest. We make no claim here about how well any product performs; that is a question for a licensed applicator, and the timing matters more than the product because the treatment has to be in place before the insects arrive.
What should I not do?
Do not squash them, because University of Kentucky Extension notes the odor is released when they are crushed, squeezed or handled, and advises against touching your face or eyes afterward. Do not leave windows open without a screen, as Virginia Tech’s Thomas Kuhar puts it. And do not expect indoor treatment to fix a problem whose cause is outdoors.
Sources
- University of Kentucky Entomology (Potter and Bessin). Stink Bug Infestation of Dwellings (ENTFACT-654). Revised March 2026. https://entomology.ca.uky.edu/ef654
- Penn State Extension (Skvarla; originally Jacobs). Brown Marmorated Stink Bug. Updated June 24, 2026. https://extension.psu.edu/brown-marmorated-stink-bug
- Penn State Extension (Skvarla). Multicolored Asian Lady Beetle. Updated August 12, 2026. https://extension.psu.edu/multicolored-asian-lady-beetle
- Virginia Tech News (Thomas Kuhar, Department of Entomology). Stink bugs: The good, the bad, and how to get rid of them. October 27, 2023. https://news.vt.edu/articles/2023/10/stink_bugs_expert.html
- Ohio State University Extension (Boggs and Jones). Multicolored Asian Lady Beetle (ENT-44). June 2, 2014. https://ohioline.osu.edu/factsheet/ENT-44