If you’re in Michigan and seeing more stink bugs around your windows and siding this time of year, you’re not alone. July marks the start of what can quickly become a full-blown stink bug invasion in Michigan homes.
These bugs might not bite, but once they’re in, they’re tough to get rid of, and their smell is hard to forget. The brown marmorated stink bug, Halyomorpha halys, is an invasive species that first appeared in the U.S. in the mid-1990s and has since spread across the Midwest.
By the time fall rolls around, these pests start looking for warm places to overwinter, and your house fits the bill. Here’s how you can keep them out now before they settle in for the season.
Key Takeaways
- Stink bug invasions in Michigan start in July and peak as temperatures drop.
- Brown marmorated stink bugs are invasive and drawn to homes as a place to overwinter.
- Sealing entry points and reducing outdoor attractants are key to prevention.
- Professional pest control may be necessary for homes with repeated infestations.
What Attracts Stink Bugs to Homes in Michigan?
Stink bugs become a problem in July because they start preparing early for overwintering. You’ll notice them sunning themselves on the south and west sides of buildings, especially on warm days. These bugs don’t want to be outside come October; they’re looking for shelter.
Michigan’s Lower Peninsula has become a prime spot for brown marmorated stink bugs. Areas like Grand Rapids, Lansing, and Detroit experience high activity due to the presence of dense housing and nearby tree fruit farms. The USDA and Michigan State University’s entomology departments have tracked their spread, noting they’ve now established themselves across most of the state.
How to Spot a Stink Bug Problem Early
You’ll often first notice stink bugs in the early morning or late afternoon, as they crawl near windows, siding, or porch lights. They’re shield-shaped, brown or gray, and have long antennae with white bands. You might even hear them buzzing clumsily around light fixtures.
If you start seeing them indoors this time of year, that’s a sign they’ve already found a way in. Common entry points include:
- Cracks around window frames and siding
- Gaps under doors without proper weather stripping
- Chimneys, soffits, and attic vents
- Loose-fitting electrical outlets or ceiling fans
Why Stink Bugs Are So Hard to Get Rid Of
One of the biggest mistakes you can make? Squish them. Stink bugs release an odor from their scent glands when threatened. It’s not dangerous, but it’s unpleasant and lingers.
These bugs don’t reproduce indoors, but once they’re inside, they hide in wall voids, attics, and behind baseboards. Then, on the first warm day, they come crawling out again, sometimes by the dozens.
Preventing a Stink Bug Invasion in July

Now is the best time to get ahead of the problem. Once they’re inside, it’s much harder to get rid of stink bugs. That’s why prevention is key. Here’s what you can do:
Seal Cracks and Entry Points
Check around your windows, siding, utility pipes, rooflines, and any crevices where stink bugs might squeeze through. Use caulk to seal cracks and apply fresh weather stripping around doors and windows. Don’t forget attic vents; screening those off can make a big difference.
Turn Off Outdoor Lights
Stink bugs are drawn to light. Keep porch lights off when you’re not using them, especially in the evening. Switching to yellow-hued bulbs can also make your home less attractive.
Remove Food Sources
In your yard, stink bugs feed on fruit trees, soybeans, and ornamental plants. While you can’t eliminate everything, trimming back overgrown vegetation near the house and harvesting fruit promptly helps reduce the number of attractants.
What About DIY Remedies?
You can try trapping a few with a pan of soapy water under a light source; some will fall in and drown. Vacuuming also works, but use a vacuum with a disposable bag. Once they’re inside, odors linger.
While over-the-counter sprays might seem tempting, most don’t do much beyond short-term relief. If you’re seeing stink bugs inside your living space consistently, it’s time to call in the pros.
When to Bring in Pest Control
Repeated stink bug invasions are frustrating, and sometimes even airtight sealing isn’t enough. Pest Pros of Michigan offers targeted treatments around key entry points, such as soffits, attic vents, and wall voids, which are spots that most DIY methods can’t reach effectively.
We’ve helped homeowners from Ann Arbor to Detroit who were overwhelmed by the sheer number of bugs crawling out during warm spells. Our technicians are specifically trained to handle stink bugs, and we tailor each treatment to your home’s unique construction and history of infestation.
Final Thoughts
A stink bug invasion in Michigan can feel like a slow-moving problem, until it isn’t. By the time fall hits, these bugs are already inside. The best defense is starting early. Sealing up your home, cutting back outdoor attractants, and knowing what to look for will help you stay ahead.
If you’ve tried everything and stink bugs still find their way inside, we’re here for you. Our team at Pest Pros of Michigan knows how to deal with invasive pests in Michigan homes, and we’re just a short drive away, whether you’re in Grand Rapids or Detroit.
Let’s stop the stink before it starts. Please call us if you need assistance.
FAQs
When do stink bugs start invading homes in Michigan?
Stink bugs typically begin invading homes in Michigan in July, as they prepare to find shelter for overwintering. By fall, they’re often inside wall voids, attics, or behind baseboards.
How can I keep stink bugs out of my house?
The best way to keep stink bugs out is to seal cracks, install screens on vents, and reduce outdoor lights that attract them. In some cases, professional pest control may be needed.
Do stink bugs cause damage inside the home?
Stink bugs don’t cause structural damage or reproduce indoors, but they can create unpleasant odors and become a nuisance when they emerge during warm spells.