A recent lab experiment uncovers that bed bugs strongly avoid water and moist surfaces, opening doors to innovative pest control methods. The common bed bug, Cimex lectularius, thrives in homes as a persistent blood-feeding pest, notoriously hard to eradicate.
Global Bed Bug Resurgence
Research highlights a worldwide increase in bed bug infestations over the past two decades, driven largely by the pests’ resistance to traditional chemical treatments. Scientists continue to explore their behavior to develop more effective strategies.
Why Water Terrifies Bed Bugs
The study demonstrates that bed bugs steer clear of wet areas, a previously unrecognized trait. This aversion aligns with their anatomy: ultra-flat bodies and tiny breathing spiracles along their abdomens. “If they physically contact a body of water, they’ll get stuck to its surface, blocking their respiratory openings,” explains Dong Hwan Choe, an entomologist at the University of California, Riverside, and study author published in the Journal of Ethology. “Due to its strong adhesive power, water could be very dangerous from a bed bug’s perspective. So, it is not surprising to learn that they’re extremely averse to moisture,” adds Dr. Choe.
The Accidental Breakthrough
During standard lab maintenance, researchers housed bed bugs in vials topped with an artificial blood feeder. A damaged membrane caused blood to leak onto grip paper inside the vial. “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,” Dr. Choe recounts. “But what I saw was very different. They were actively avoiding the part of the paper that became wet with blood. They wouldn’t even walk near the wet areas.”
Follow-up tests confirmed the pattern: dampening paper with plain water prompted identical avoidance. Every bed bug tested—regardless of age or sex—shunned wet surfaces, often executing swift U-turns to retreat faster than they approached.
Practical Control Implications
These insights suggest straightforward tactics for managing infestations. “Take a bath. It’ll solve the problem,” Dr. Choe advises for suspected bugs on the body. “Of course, the bed bugs in the room or on the bed will require different approaches.”
