Thanks to the advent of cheap travel, bed bugs are thriving. So far, little research has been conducted to understand how best to prevent these bloodsuckers from boarding transcontinental flights and returning home with travelers.

New research published Thursday in Scientific Reports finds bed bugs are attracted to dirty laundry. The revelation makes a lot of sense, as these bugs find their meals by going to places where human scents are present. Previous research has noted physiological and behavioral changes in bed bugs when they’re near a breathing human.

“Potential ‘vehicles’ for passive dispersal, such as luggage, are likely to contain recently worn clothes (i.e., those soiled with sweat and volatiles) that release human odor, especially since travelers tend to take home their dirty laundry,” the researchers write in their study. “Odors from soiled clothing (or luggage containing soiled clothing) may therefore influence host-searching behavior in bed bugs and consequently facilitate the passive dispersal of bed bugs via long-distance transport networks.”

For the study, researchers recruited four volunteers who were instructed to bathe with unscented soap and then wear white cotton T-shirts and socks. After three hours they sealed the clothing items in ziplock bags. The researchers then washed the clothing from two of the volunteers. Next, they placed the clean and the soiled clothing in four clean duffle bags.

They conducted the experiment in two identical, temperature-controlled rooms. During each round of the experiment, the researchers designated one room to have elevated levels of carbon dioxide, to simulate the presence of a human. The researchers set the bugs free in the rooms shortly after they’d received blood meals.

The researchers found that even in the absence of a human host, bed bugs were twice as likely to end up in the bags with dirty clothes than in those containing clean clothes. They were also surprised to see that elevated carbon dioxide levels didn’t change their behavior (i.e., it didn’t make the bugs more likely to crawl into a bag of clean clothing).

The study’s findings suggest one way travelers could avoid bringing bed bugs home is to do laundry before getting on a plane. “Careful management of holiday clothing may be an important strategy in the prevention of bringing home bed bugs,” the researchers conclude.