The Centers For Disease Control (CDC) has just issued a warning stating that bedbugs are “spreading wildly” all over the globe, with their populations increasing dramatically in Europe, Canada, and the U.S. Researchers are blaming affordable international flights and suitcases filled with dirty laundry for the spread of these bedbugs.

A new study revealed that dirty clothing is two times more likely to attract bedbugs than clean garments, which has caused experts to surmise that bedbugs are going home with travelers by hitching a ride on the dirty clothing in their suitcases.

“Bed bugs are attracted to the odor of sleeping humans and we suggest that soiled clothing may present a similarly attractive cue, allowing bed bugs to ‘hitch-hike’ around the world after aggregating in the laundry bags of travelers,” the researchers behind the study wrote. “Soiled clothing left in an open suitcase, or left on the floor, of an infested room is likely to attract bed bugs. When packed into the suitcase, they will accompany their host back home.”

Making matters worse, bedbugs are becoming harder to kill since they are becoming resistant to the pesticides traditionally used to kill them. These pesky microscopic creatures can live without blood for months, so once they’re in your house, they can stay there for weeks before they make themselves known.

To combat the spread of bedbugs, experts are warning travelers to keep their suitcase off of the floor and beds by using the luggage rack. They are also advising people to store dirty laundry in an airtight plastic bag while they travel and to wash the clothing in hot water as soon as they get home.