Stink bugs are invading IL homes right now. They aren’t the only critter headed inside
After the metro-east and greater St. Louis region saw an abnormally warm and dry September, some pests will likely stick around longer this year than usual.
Average high temperatures this September were about 4 degrees above average, National Weather Service St. Louis lead meteorologist Matt Beitscher said in a recent interview with the News-Democrat. Much of the region experienced moderate to severe drought conditions in early fall that curtailed the metro-east’s typically colorful fall foliage.
In addition to dulling autumn leaves, the delayed onset of cooler temperatures is likely to allow ants and spiders to remain active for longer than normal, Jim Fredericks, board certified entomologist and senior vice president of public affairs for the National Pest Management Association, wrote in an Oct. 23 email to the BND.
Belleville and surrounding areas are starting to move into a more normal fall weather pattern, Beitscher said in late October, and though this week’s forecast shows sun and warmer temperatures before a cooler dip this weekend.
“So while September was relatively warm and dry, we’ve seen a little bit kind of a regression back to a normal fall pattern here in October with a little bit wetter conditions,” Beitscher said.
Those cooler temperatures will bring some creepy crawlers inside.
“As temperatures continue to cool, invasive brown marmorated stink bugs are expected to move indoors to seek shelter,” Fredericks said.
Here’s what to know about pesky stink bugs and other species that may see increased activity soon.
How to keep stink bugs out of your home
Stink bugs are often found inside Illinois homes during fall and winter as they seek shelter from the cold. They tend to congregate on sunny sides of buildings for warmth.
“While they’re mostly a nuisance pest, they can emit a foul odor when crushed,” Fredericks said.
To keep stink bugs and other unwanted visitors out of your home during the fall and winter months, Fredericks said it’s a good idea to inspect the exterior of your home for gaps, especially around doors and windows, and seal up any you find.
Other best practices to mitigate the number of bugs include eliminating food and water sources, keeping your yard tidy, checking screens for any areas that need repair and storing firewood at least 20 feet away from your home and off the ground.
It’s also important to keep an eye out for any infestation warning signs, such as droppings or gnaw marks, Fredericks said, and consider calling in a professional if you do have an infestation.
If stink bugs do make their way into your home, the entomologist suggested the following steps:
- Gently vacuum them up to remove them without triggering their odor release.
- Empty your vacuum bag or canister immediately outside to avoid a reinfestation.
- Avoid crushing the creatures, as it releases a strong, lingering odor.
- Check for nearby entry points and seal any gaps discovered.
- Monitor the area for additional bugs over the next few days, as more may follow.
What other pests are common in the fall and winter?
As high temperatures in Belleville hover in the 60s, it won’t be too cold for mosquito activity. Mosquitoes tend to become less active when temperatures consistently stay below 50 degrees, Fredericks said.
Ticks are also active on days when it’s at least 50 degrees out. Because warm winter days aren’t uncommon, it’s considered the best practice to use year-round prevention for your pets, according to Cornell University’s College of Veterinary Medicine.
Rodents are another common issue in the colder months as they seek food sources in people’s homes. Rodents can host a variety of infectious diseases, so it’s especially important to keep an eye out for any rodent activity in your home.
“Illinois homes may see an uptick in spider activity indoors during the fall as they seek warmth and places to build webs for catching insects,” Fredericks said.
Some of the most commonly found spider species in Illinois homes include cellar spiders, cobweb spiders, sac spiders and brown spiders, according to the Illinois Department of Public Health.
The majority of spider species found in Illinois are not dangerous, and even the black widow and brown recluse species in the state are not aggressive. If you want to limit spider activity in your home, sealing up entry points is a good starting place.
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This story was originally published November 7, 2025 at 5:00 AM.
