Every fall, the same thing happens on warm, sunny afternoons: shield-shaped brown bugs line up on the sunny side of the house, and a few days later they are walking across the window, buzzing around the kitchen light or clinging to the curtains. This year they may show up even sooner. The National Pest Management Association’s 2026 Bug Barometer warns that a mild winter followed by a dry spring has set up an earlier stink bug season in 13 states and Washington, D.C., from Maine down to Virginia.
The good news: stink bugs are harmless to people, pets and the house itself. The bad news: the two things most people do first, squashing them and spraying them, are exactly what makes the problem smell worse and last longer. This guide explains how to get rid of stink bugs in your house the way entomologists recommend, and why the timing of each method matters more than the product you buy.
Why stink bugs come inside in the fall
The bug most people are dealing with is the brown marmorated stink bug, an insect native to China, Japan, Korea and Taiwan that was first collected in the U.S. in Allentown, Pennsylvania, in 1998. It spends summer feeding on fruit trees, vegetables and garden plants. When the days shorten, adults stop feeding and start looking for a protected place to spend the winter in a dormant state, the way they would shelter under tree bark in the wild.
To a stink bug, your house is the best bark in the neighborhood. They gather on warm, elevated surfaces facing the sun, then crawl into any gap they find: around window and door frames, behind siding, through attic and crawl space vents, and where pipes, cables and air conditioners go through the wall. Once inside the walls or the attic, they stay mostly still. On warm winter or early spring days, some wake up, follow the warmth and end up in your living space.
How many can one house hold? More than you would guess. A researcher in Washington County, Maryland, collected every brown marmorated stink bug that appeared inside their own two-story home between January and June 2011. The total was 26,205 stink bugs in 181 days. About half (13,153) were found in the attic crawlways, often in large clusters, and roughly 40% came out into the first and second floors through cracks around ceiling molding, baseboards, windows and light fixtures. None turned up in the unheated basement.
Two details from that study change how you should think about the problem. First, the bugs you see in your bedroom are usually the overflow from a much larger group hiding in the attic or walls. Second, more of them came out on days warmer than average. A sunny spell in February is when you will see them, even though they moved in back in October.
How to tell it is a stink bug (and what it will not do)
According to the University of Kentucky’s entomology department, adult brown marmorated stink bugs are:
- About 5/8 inch long, shield-shaped and mottled brown-gray.
- Marked with a white band on the antennae, on the next-to-last segment.
- Edged in alternating black and white bands where the abdomen sticks out from under the wings. Native brown stink bugs do not have this checkered edge.
What they will not do matters just as much, because it should take the panic out of the situation. The University of Maryland Extension notes that they do not bite or sting, do not spread disease and do not eat or bore into wood. Washington State University adds that they do not reproduce indoors. The stink bugs in your house in November are the same ones that will try to leave in spring. You are not facing a growing colony, only a crowd of lodgers.
Step 1: Seal the house before they move in
Every extension service agrees on this point: keeping them out is the only method that really works. Maryland Extension calls mechanical exclusion “the best method to keep stink bugs from entering homes and buildings.” The best time to do it is late summer and early fall, before they start gathering on the walls. If they are already on the siding, do it anyway, because new ones keep arriving for weeks.
Walk around the outside of the house on a sunny afternoon and look where the bugs are gathering. That is where they are getting in. Then work through this list:
| Where to check | What to do |
|---|---|
| Window and door frames | Fill gaps with silicone or silicone-latex caulk |
| Window screens | Repair tears and make sure screens fit tightly |
| Exterior doors | Add or replace door sweeps and weatherstripping |
| Attic and crawl space vents | Cover with insect mesh fine enough to block bugs |
| Pipes, cables, AC lines, dryer vents | Seal around each opening with caulk or foam |
| Siding corners and fascia boards | Caulk cracks, especially under wood fascia |
| Outdoor lights | Turn them off when not needed or switch to yellow bulbs |
Sources for this checklist: University of Maryland Extension, Washington State University and the NPMA. The same gaps let in mice when the temperature drops, so if you are already sealing for one, you are sealing for both. Our guide on how to get rid of mice covers the larger openings.
Inside, check the places where the Maryland study saw bugs coming out: around ceiling light fixtures, exhaust fans, baseboards and window trim. A thin bead of caulk along those cracks stops many of them from reaching your rooms, even if they are already in the walls.
Step 2: Remove the ones already inside, without the smell
Stink bugs release their odor when they feel threatened or are crushed. The smell fades on its own, but there is no reason to set it off in the first place. These are the two methods extension entomologists recommend.
The soapy water container
This is the method the University of Maryland describes, and it costs nothing:
- Cut the top off a straight-sided plastic container that holds half a gallon to a gallon.
- Fill about a quarter of it with water and add a teaspoon of liquid dish soap. The soap breaks the surface tension, so the bugs sink instead of floating.
- Hold the container under the bug and tap or sweep it in with a piece of cardboard. Stink bugs drop downward when disturbed, so they usually fall straight in.
- For bugs on high walls or curtains, tape the container to a broom handle and slide it up underneath them.
The vacuum, with one trick
Vacuuming works for clusters in corners or on ceilings, but a regular vacuum can smell of stink bugs for a while afterward. Maryland Extension’s solution: slip a knee-high nylon stocking over the end of the hose and secure it with a rubber band, pushing part of it inside the tube. The bugs get caught in the stocking instead of the canister. Turn off the vacuum, pull off the stocking and empty it into soapy water. If you vacuum them directly, seal the bag and put it in the outside trash right away, as Washington State University advises.
Step 3: Use a light trap, but at the right time of year
If you search for stink bug traps, you will find dozens of commercial models. In 2012 and 2013, Virginia Tech researchers asked homeowners in Virginia to test several of them against a homemade design in their own houses. The results, published in the Journal of Extension, were clear: the homemade trap caught 19 times more stink bugs in 2013 than the other two traps tested, including a commercial model that cost about $30.
The trap costs about $10 to put together:
- A disposable aluminum roasting pan, the kind sold for turkeys.
- About a quart of water with a small squirt of dish soap.
- A desk lamp placed next to the pan and aimed into the water. The researchers used a 13-watt CFL bulb. Make sure the lamp cannot tip into the water.
Put it in a dark room where you see bugs, turn off the other lights and leave the lamp on overnight. Some participants caught up to 144 bugs a week.
Here is the part most articles leave out: the study ran in winter and spring, when stink bugs wake up and move toward light. In the fall, when they are looking for a dark place to hide, they are far less drawn to it. The project’s researchers told WVTF public radio that the trap works when stink bugs are attracted to light in spring and will not work the same way in autumn. So in October and November, seal and vacuum. Save the light trap for the warm days of late winter and spring, when the bugs hiding in your attic start coming out.
Common mistakes that make it worse
Squashing them
Crushing a stink bug releases the odor and can leave a stain on walls, curtains or fabric, as the University of Kentucky warns. A paper towel is not enough protection. Use the soapy water container instead.
Setting off a bug bomb
Foggers do not reach the bugs hiding inside walls and do nothing to stop new ones from coming in. Washington State University does not recommend pesticides inside the home for stink bugs at all.
Putting insecticide dust in the walls or attic
This one surprises people. Dust can kill a lot of stink bugs in a wall void, but then you have thousands of dead insects where you cannot reach them. According to Maryland Extension, carpet beetles may then feed on the dead stink bugs and move on to damage wool clothing, blankets, stored dry goods and other natural materials. You trade a harmless winter guest for a pest that eats your sweaters.
Expecting an outdoor spray to solve it
Exterior insecticides can give some relief where sealing is not possible, but sunlight breaks them down, so they may only work for a few days to a week. If you use one, Maryland Extension suggests applying it in the fall just before the bugs gather, and only to the window sills and door thresholds listed on the label, not to the foundation or mulch. Caulk lasts for years. A spray lasts days.
Leaving the porch light on all night
Outdoor lighting draws insects to your doors and windows. The NPMA recommends turning off unnecessary outdoor lights or switching to yellow bulbs, which attract fewer insects.
When to call a professional
For most homes, sealing and a soapy water container are enough to keep things manageable. Consider calling a licensed pest control company if:
- You are finding dozens of bugs indoors every day, which usually means a large group in the attic or walls.
- The bugs are getting in through places you cannot reach safely, such as high siding, the roofline or chimney flashing.
- The problem comes back every year despite your sealing. A professional can find entry points you missed and, if needed, apply an exterior treatment at the right moment in the fall.
Your fall stink bug plan
| When | What to do |
|---|---|
| Late summer to early fall | Caulk gaps, fix screens, add door sweeps, screen vents |
| October and November | Remove indoor bugs with soapy water or a vacuum; seal the cracks they come out of |
| Warm days in winter | Expect a few to wake up and appear near windows and lights |
| Late winter and spring | Set up the pan and lamp trap in rooms where they appear |
Stink bugs are one of several pests that move indoors when the weather turns. If you are also seeing tiny flies around the fruit bowl, our guide on how to get rid of fruit flies walks through finding the source. And for the rest of your cold-weather prep, see the fall home maintenance checklist.
Sources: National Pest Management Association, 2026 Bug Barometer; University of Maryland Extension; University of Kentucky Entomology; Washington State University PestSense; Journal of Entomological Science, “Characteristics of Home Invasion by the Brown Marmorated Stink Bug”; Journal of Extension, light trap study.