CBS Local — Scientists have found a new defense against bringing bed bugs into your home. The solution in simple: wash your clothes.

British researchers from the University of Sheffield say that leaving dirty laundry exposed in bedrooms while traveling may lead to bed bug infestations. The scientists report that the blood-sucking, itch-causing pests are not only attracted to humans but also the smell of humans which dirty clothes carry.

“There are a lot of good studies out there focused on trying to understand how bed bugs are attracted to humans and how they get around apartment blocks, but no one has really talked about how they get into the house in the first place,” according to the study’s author William Hentley. To find the answer, Hentley and his team tested two identical rooms which both had a bed, a pile of dirty clothes, and a pile of clean clothes in it. One of the rooms had carbon dioxide pumped into it so the researchers could simulate a human breathing; which bed bugs are known to seek out. The results found that bed bugs were likely to go after the “human” if they sense one nearby however. In the room with no human, the bed bugs were twice as likely to settle on dirty clothes than clean ones.

Scientists believe the increase in bed bug cases around the world is due the growing ease of international travel. The study urges people to keep their worn clothing in sealed bags, especially while they’re travelling and leave their hotel room.

“Once a room is infested with bed bugs, they can be very difficult to get rid of, which can result in people having to dispose of clothes and furniture that can be really costly,” Dr. Hentley added. “Bed bugs are a huge problem for hotel and homeowners, particularly in some of the world’s biggest and busiest cities.”