What Causes Bed Bugs?

Bed Bugs Need Blood to Thrive

Bed bug feeding.
Bed bugs don't care if you're rich or poor, or how clean your home is. They just want blood. John Downer/The Image Bank/Getty Images

Once considered a pest of the past, bed bugs now make regular headlines as they infest homes, hotels, and dormitories worldwide. As bed bugs spread, more people are worried about them and want to know what causes bed bugs.

Though it may seem like bed bug infestations are on the rise, historical context is important. Bed bugs and other bloodsucking parasites have been associated with humans for thousands of years.

Throughout history, people have endured insects feeding on their blood. Bed bugs all but disappeared when people started using DDT and other pesticides to keep insects out of their homes. So although news headlines suggest bed bugs are conquering the world, the reality is that bed bug infestations are still at historically low numbers.

Bed Bugs Don't Care if You're Clean or Dirty

Contrary to popular belief, there is no association between bed bugs and filth. Bed bugs feed on human and animal blood.  As long as there's a source of blood available to them, they will happily take up residence in even the most pristine home. ​Dirt does not cause bed bugs.

Similarly, bed bugs don't care how much money you make. Being poor does not put you at greater risk for bed bugs, and having wealth does not immunize you from a bed bug infestation. Poverty does not cause bed bugs. However, impoverished communities may lack the resources needed to control bed bug infestations, making them more persistent and pervasive in such areas.

Bed Bugs Are Excellent Hitchhikers

For bed bugs to infest your home, they've got to hitch a ride on someone or something. Bed bugs don't usually stay on their human hosts after feeding, but might hide in clothing and inadvertently go along for the ride to a new location. Most often, bed bugs travel in luggage after someone has stayed in an infested hotel room.

Bed bugs may even infest theaters and other public spaces and spread to new locations via purses, backpacks, or coats.

Bedbugs Go Where the Action Is

Because bed bugs travel by hitchhiking, infestations are more common in places with high rates of turnover in the human population: apartment buildings, dormitories, homeless shelters, hotels and motels, and military barracks. Any time you've got a lot of people coming and going, there's an increased risk that someone will carry a few bed bugs into the building. In general, homeowners of single family homes have a lower risk of getting bed bugs.

Bed Bugs Hide in Clutter

Once in your home, bed bugs can scurry quickly to a new hiding place: behind baseboards, under wallpaper, inside switch plates, or in furniture seams. Then it's just a matter of time before they begin multiplying. A single female may arrive at your doorstep already carrying enough eggs to produce hundreds more offspring. And while filth does not benefit bed bugs in any way, clutter does. The more cluttered your home, the more hiding places for the bed bugs, and the harder it will be to get rid of them.