Bed Bugs Are Picky About Certain Colors

Given that female bed bugs lay over 200 eggs during their lifetime, it’s not surprising that an estimated one out of five American households have had or know someone who has had a bed bug infestation. But a new study shows that an unexpected weapon may be useful in the fight against the tiny, biting menaces: color. The BBC’s Michelle Roberts reports that bed bugs appear to have strong preferences (and disdains) for certain colors.

The unexpected information about bed bugs’ aesthetic preferences comes via a study recently published in the Journal of Medical Entomology. A group of researchers became curious about whether bed bugs like certain colors, so they created tiny tents, or harborages, from colored card stock and placed them in petri dishes. The researchers then took bed bugs of different maturities, genders, sizes and hunger levels and put them on the center of the dish, giving them ten minutes to choose which harborage they wanted to hide in.

Bed bugs are nest parasites—that’s why they love human “nests,” or bedrooms. So they’re obsessed with finding shelter. As a result, it would make sense that a bug placed on the scary expanse of a petri dish would scurry for cover as soon as possible.

But not the bed bugs in this experiment. Rather than run to any old harborage, they overwhelmingly ran to black and red harborages, passing by ones of other colors. And they weren't into yellow or green at all. Overall, the bugs preferred harborages in this order: red, black, orange, blue, lilac, violet and green. Gender influenced the decisions, as did how hungry the bugs were, and groups of single-gender bugs preferred the same colors. Researchers speculate that the decisions may have to do with bugs’ assessment of different shelters as better or worse places to mate or perhaps stay safe from predators.

"We originally thought the bed bugs might prefer red because blood is red and that's what they feed on," says Dr. Corraine McNeill, one of the co-authors of the paper, in a release. "However, after doing the study, the main reason we think they preferred red colors is because bed bugs themselves appear red, so they go to these harborages because they want to be with other bed bugs, as they are known to exist in aggregations."

But before you go out and buy a new sheet set, know that there’s a catch: These experiments were conducted in full light.

The researchers admit that bed bugs like to eat and find shelter during dark periods, so their favorite colors may not apply. Still, knowing what colors bed bugs like and loathe could help create better traps—and help humans scare them away during the light of day. After all, humans have favorite colors—why shouldn't that apply to the bugs that torment them?

Erin Blakemore | | READ MORE

Erin Blakemore is a Boulder, Colorado-based journalist. Her work has appeared in publications like The Washington Post, TIME, mental_floss, Popular Science and JSTOR Daily. Learn more at erinblakemore.com.