In many places, bed bugs are becoming a common trouble. But scientists say that cheap ultrasound devices advertised as bed bug repellents do not work. Caroline Custer/Associated Press hide caption

In many places, bed bugs are becoming a common trouble. But scientists say that cheap ultrasound devices advertised as bed bug repellents do not work.

Nowadays, bed bugs are almost everywhere, and people fighting with blood-sucking insects may want to try to get rid of them.

However, entomologists who tested certain devices said that ultrasonic insect killers, which retail for less than $25, are not the solution.

Kasey Yturralde, a graduate student in entomology at Northern Arizona University, said: “On a personal level, I can understand that you want to do your best to get rid of them and protect yourself.” In 2006, she met her friends while visiting them. It was an unforgettable trip. "It's very painful," she told Shots.

Recently, Yturralde and her co-author Richard W. Hofstetter tried four different ultrasound devices on Amazon: one designed for bed bugs, and the other three claiming to repel insects and small furry mammal pests.

Their simple experimental design consists of two 5-gallon barrels lined with soundproofing material and connected by pipes. An ultrasonic device was placed in a bucket, and eight to ten bed bugs were placed in the tube.

More attention has been paid to the way bed bugs are reared in the laboratory. The researchers stored them in large jars, just like the jars used for canning cans. These jars were placed in boxes filled with soapy water. Yturralde said that every lip or edge that rogue bugs must crawl over is covered with a smooth substance that resembles liquid polytetrafluoroethylene to prevent them from escaping.

In test after test, the bug has no preference for any bucket. "They are evenly distributed in the two arenas," Yturralde points out. None of the four devices repelled bed bugs.

It is not entirely illogical to think that ultrasonic frequencies may have an effect on bed bugs. After all, the bark beetles Yturralde and Hofstetter usually study communication in the ultrasonic range. These devices may interfere with erroneous communication. But, of course, not all wrong behaviors are the same.

"These devices have been tested with other insects, but they have not shown any effect," Yturralde said. She said that now people can know that they will not be effective against bed bugs, "and switch to other methods of elimination."

The results were published in the "Journal of Economic Entomology".