Do Ultrasonic Pest Repellents Actually Work?
In many cases, DIY pest control has some risks and downsides and you may just wind up spending more in the end in an attempt to control a pest problem on your own.
Many homeowners often turn to DIY pest repellents in order to save money. And ultrasonic pest devices and plugins make a big, bold promise: effortless pest removal with the push of a button. Despite manufacturers claiming ultrasonic machines affect all these different species, well-constructed research does not support these claims.
Ultrasonic pest repellers are electronic devices that emit high-frequency sounds designed to repel, injure or kill household pests, such as rodents and insects. The manufacturers behind ultrasonic pest control devices claim that a wide range of pest species don't like the sounds and vibrations emitted by the machines. Rather than put up with the annoying noises from the device, the pests may flee your home and garden and seek refuge in areas not blanketed by the high-frequency sounds. A related group of pest control machines, known as "subsonic pest repellers," work in a similar fashion and use very low-frequency sounds or vibrations. The claim is the same: Unwanted animals and insects find the noise impossible to withstand and vacate the premises.
These ultrasonic devices are plugged into a home’s electrical receptacle outlets which then purportedly emit high-frequency sounds that are disruptive to pests. The sound supposedly causes a physiological response known as audiogenic seizure response, which is characterized by non-directional running, convulsions, and possibly death from cerebral hemorrhage. The theory behind the devices is that confused rodents eventually flee when the disruption prevents them from gathering food, breeding, building nests or communicating. Ultrasonic devices are popular and appealing to consumers because of their ease of use and the fact that they are silent to human ears (although some are audible) and allegedly eliminate the need for traps and poison, which are thought by some to be inhumane forms of pest control.
Studies designed to investigate the efficacy of ultrasonic pest repellents have shown mixed results. One extensive test performed by Kansas State University in 2002 found that the devices were effective at repelling some insects, such as crickets, but the same devices had little effect on cockroaches. Ants and spiders were unaffected by any of the devices. Of the pests that seem to be bothered by the noise, some tests have shown that they soon become habituated as they realize the noise is harmless. Even models proven successful in tests are unlikely to perform adequately in real-world situations, where signal strength rapidly diminishes and can be blocked by walls and furniture.
A study on how ultrasonic pest repellers affect bed bugs found that bed bug activity did seem to change slightly when the devices were running. However, in the end, there was no statistical difference when compared to not using an ultrasonic pest repeller. Similarly, a 2015 study conducted by the University of Arizona concluded that, although the number of patents for ultrasonic pest repellents had increased over the years, commercially available ultrasonic pest devices were not an effective means of treating pest problems.
And even when they do work, the effects are short-lived. For instance, a study of rodent repellent devices for the United States Department of Agriculture and the National Wildlife Research Center found that rodents stopped responding to the ultrasonic sounds after just a few days of exposure.
Sometimes, ultrasonic devices don't just fail to chase away pests. They might even have the unintended effect of doing exactly the opposite and making pest problems worse. A study recorded in the Journal of Vector Ecology investigated the impact that ultrasonic pest repellers had on mosquitoes. When turned on, the devices actually increased the rate of mosquito bites by 50 percent.
Safety concerns have arisen, too; the noise may also cause inadvertent distress to rabbits and rodent pets, such as guinea pigs and hamsters. Cats and dogs can hear in the ultrasonic range, but they appear not to be bothered by the noise emitted by these devices.
Manufacturers of ultrasonic pest repellers make claims that may be unsupported by scientific testing. In summary, ultrasonic pest repellers emit high-frequency sounds that manufacturers claim reduce household pest infestation, but laboratory tests have shown that the majority of such devices do not work as advertised. While some ultrasonic repellents may have a minor short-term impact on some pests, the research is nearly universal: Ultrasonic pest repellers are not an effective option for preventing or eradicating pests.
Homeowners with pest problems should rely on a qualified inspector who can help them identify their particular pest problem and advise them on practical and effective solutions.
