Scientists Discover What Terrifies Bedbugs

Bedbugs, it turns out, really don't like to get their feet wet. Researchers at UC-Riverside report that the household pests strongly avoid damp surfaces, a finding that emerged by accident when a lab feeding device leaked blood into a vial of bedbugs—and the insects refused to go near the soaked paper at the top of the container, per Gizmodo. "I thought the bedbugs would be happy to drink the blood from the paper," study co-author Dong-Hwan Choe says in a statement. "But what I saw was very different."

Follow-up experiments with plain water showed the same pattern: The bugs spent far less time on wet areas, and nearly 90% of the time they changed direction before even contacting the moisture. Younger "nymph" bedbugs were about 60% faster than adults at steering clear, suggesting an especially sharp sensitivity. The team suspects water is dangerous for the insects because their flat bodies and tiny breathing openings could be easily overwhelmed by liquid. The study, published in the Journal of Ethology, suggests pest control pros should rethink how they use liquid insecticides. If the chemicals don't kill on contact, the bugs may simply flee the treated, wet surfaces and spread elsewhere.