Why are stink bugs still creeping into WA homes? We know where they’re coming from
It seems like the stink bug is one creature that will never go away this winter.
The invasive species, which originates in China and Japan, first made their way to the U.S. in the mid-1990s. It has continued to crawl its way into Washington state homes this winter, since the colder months of the year are when adult stink bugs regularly look to relax inside human habitations like attics or sheds, according to Washington State University.
To many people, it may not be immediately clear how or why stink bugs are inside homes in the winter. Others may be curious as to why there seem to be more of the bugs than ever before.
The News Tribune asked a pest control specialist for answers.
Why are there so many stink bugs in WA this winter?
If you’re finding a larger-than-normal number of stink bugs in your home this winter compared to previous years, don’t worry. Stink bugs are cyclical creatures, which means It’s normal to encounter them in higher numbers some years compared to others, according to Kevin Peterson, an operations manager with Cascade Pest Control.
“Certain years you’re going to have more of these than you are in other years,” Peterson said. Over the past several months, Cascade Pest Control has received more calls from customers encountering stink bugs compared to winter seasons in previous years, he said, though he didn’t specify how many more calls the company has seen this year than in others.
There are a few reasons why stink bugs could be popping up more often now. One is related to changes in the weather. Peterson notes that stink bugs are more sensitive to temperature change than humans. When it gets cold outside and people turn the heat up, the temperature increase confuses the bugs hiding in an attic or confined space and they may move to a more visible area.
Another reason you may be seeing stink bugs more often than before is entirely due to chance. Your house just may be one of the random locations that the bugs chose to inhabit during winter.
“It’s just their normal process of looking for places where they might be able to shelter through the winter and to continue in the next season,” Peterson said.
Where are stink bugs hiding?
Stink bugs want to hide away in unreachable spaces to wait for winter to end, Peterson said. In many cases, our homes fulfill that purpose until spring, at which time the bugs will try to get out of the home, according to pest control resource website Pest World.
The insects may be tucked away in indoor spaces unreachable to humans and even small rodents. And outside, they may find safety inside the tight spaces of tree bark or shrubs.
What attracts a stink bug?
Although stink bugs may be in or around your home just so they can outlast the colder season, they may be more attracted to certain spots than others.
For instance, the insects will move toward lighted areas. During the winter time, they may congregate to windowed areas facing northwest and southwest, in view of the sunrise and sunset, respectively, Peterson said. These windows can reflect a lot of light indoors. And in the evening, your porch or patio lights are also beacons to them, according to pest resource website Home Pest Removal.
Finally, the stink bug’s eponymous odor also serves to attract surrounding bugs. It emits this odor when it feels threatened or even after it dies and starts decomposing.
How to prevent or get rid of stink bugs
If you’re coming across stink bugs in your house, there are a few things you can do to safely remove them and prevent them from re-entering:
Don’t squish them, as this may cause staining or allow the bug’s odor to disperse.
Use a vacuum to suck up the bugs. Empty the remains into a trash bag, tie it shut, then place it in the garbage.
Alternatively, place them in a container, then fill it with 4 to 5 inches of soapy water.
Pull down shades at windows that reflect a lot of light. Start at ones on the northwest and southwest regions of your home.
Limit how often you keep your porch or patio lights on, or replace what light bulbs you use. For instance, yellow bulbs are less attractive to the insects.
Fill small openings to the outside, such as repairing a crack in the window or installing door sweeps.
If you don’t want to kill the insect, one way to actively repel the bug is to use essential oils like mint, according to website The Pest Rangers. Stink bugs and other insects hate the aroma, which isn’t poisonous.
To simply catch and release bugs outside unharmed, Zunex Pest Control recommends making your own trap using a soda bottle and LED light. The makeshift device will attract stink bugs and trap them inside for you to release later.
This story was originally published January 10, 2023 at 9:00 AM with the headline "Why are stink bugs still creeping into WA homes? We know where they’re coming from."