CHICAGO (CBS) — This is the time of year when stink bugs make their way indoors. If you have them in your house, you’ll know.

While he’s smelled plenty of other stink bugs in his work as a field and crop entomologist for the University of Illinois Extension, Nick Seiter hasn’t smelled the brown marmorated stink bug, which is showing up in Chicago area homes now.

“To me, it’s a difficult smell to describe — it’s very distinct,” Seiter said. “It’s fairly potent, particularly if you disturb one.”

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Rotting vegetation is the common description for the invasive species that squeeze in through tiny cracks. Peter Schopen of Schopen Pest Solutions added, “Theses particular bugs, stink bugs, feed on produce. They feed on vegetables, pear trees, apple trees.”

“Seal up those cracks and crevices wherever you can. Make sure there’s not spaces between the windows,” Seiter advised.

Once inside, Seiter suggests vacuuming the bugs up, with care not to smash them, as they could leave behind not only a stink, but also an orange-yellow color.

It’s believed the first stink bugs arrived in the United States in Pennsylvania nearly 20 years ago, in shipping crates from China.