Bed Bugs Dread Water, New Study Finds

Researchers discover bed bugs have a strong aversion to wet surfaces, which could improve pest control efforts.

Published on Feb. 24, 2026

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A recent study from the University of California, Riverside has found that bed bugs have a strong aversion to water and wet surfaces. The researchers discovered this by accident when they noticed bed bugs avoiding a leaky blood-filled feeding machine. Further experiments showed that bed bugs, especially younger ones, will actively move away from wet areas before even coming into contact with the water. The researchers believe this is likely due to the strong adhesive force of water, which could block the insects' external breathing pores and potentially drown them.

Why it matters

Bed bugs have made a resurgence in recent decades, and traditional insecticide-based pest control methods are becoming less effective as the insects develop resistance. These new findings about bed bugs' fear of water could help improve liquid-based pest control tactics and make them more effective at eradicating these stubborn pests from homes.

The details

In the study, researchers at UC Riverside closely tracked how bed bugs, both young and old, male and female, moved in the presence of wet versus dry surfaces. They found that nearly 90% of the time, the bugs moved away from the wet surfaces before even coming close to touching the water. Younger bed bugs, or nymphs, were about 60% quicker than older bugs at turning away from water, suggesting an especially strong aversion. The researchers believe this aversion is likely due to the threat of the strong adhesive force of water blocking the bed bugs' external breathing pores, which could easily drown them.

  • The study was published in the Journal of Ethology in December 2025.

The players

Dong-Hwan Choe

An entomologist at the University of California, Riverside who led the research on bed bugs' aversion to water.

University of California, Riverside

The research institution where the study on bed bugs' water aversion was conducted.

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What they’re saying

“These findings demonstrate that the wet surface is intrinsically aversive to bed bugs, a factor that must be considered in the development and application of liquid-based control tactics to prevent bed bugs from evading freshly treated surfaces.”

— Dong-Hwan Choe, Entomologist (Journal of Ethology)

“The leaked blood was slowly soaking the paper from the top of the vial. I thought the bed bugs would be happy to drink the blood from the paper. But what I saw was very different. They were actively avoiding the part of paper that became wet with blood. They wouldn't even walk near the wet areas.”

— Dong-Hwan Choe, Entomologist (University of California, Riverside)

What’s next

The researchers plan to further investigate how bed bugs' aversion to water could be leveraged to improve liquid-based pest control methods and make them more effective at eradicating bed bug infestations.

The takeaway

This study's discovery that bed bugs have a strong fear of water could lead to more effective pest control strategies that don't solely rely on insecticides, which bed bugs are increasingly developing resistance to. Incorporating an understanding of bed bugs' water aversion into liquid-based removal methods may help exterminators better combat these stubborn indoor pests.