Several types of plug-in devices claim to repel rodent and insects, using high-frequency sound waves or vibrations. They are often promoted as eco-friendly alternatives to pesticides and poisons. Depending on the product, they may claim to repel mice, rats, squirrels, birds, bats, fleas, cockroaches, silverfish, spiders, ants, mosquitoes and many other pests. But these devices remain controversial, because scientific test results do not always agree with the advertised claims these devices make.
Plug-in pest repellents claim to repel pests using ultrasonic or electromagnetic signals. Electromagnetic devices send a pulsating signal through your home's electrical wiring. Ultrasonic devices uses sound frequencies that are inaudible to humans. Although pets are capable of hearing many of the same sound frequencies as rodents and insects, these devices are considered "safe" for pets, because they do not harm them.
According to Barb Ogg, an extension education with the University of Nebraska, research studies have shown that ultrasonic devices do not work effectively at repelling or eliminating pests from buildings. Electromagnetic devices are also ineffective, according to a symposia conducted by Stephen Schumake at the 1995 National Wildlife Research Center Repellents Conference. Because scientific studies did not support some of the claims companies made about these products, the Federal Trade Commission (FTC) went after them for false advertising in the 1980s and '90s.
Between 1985 and 1997, the Federal Trade Commission (FTC) charged six manufacturers of electronic pest devices with false advertising. The companies were required to make refunds, but the products were not removed from the shelves. In 1991, the FTC sent letters to over 60 manufactures of ultrasonic pest-control devices, warning them that any claims made must be supported by scientific evidence. Specifically, they challenged any claims that the devices could eliminate rodent infestation, repel insect and be used as alternative to traditional pest control methods. In 2003, the FTC went after a company that continued to make these claims without the proper evidence and forced them to stop. The company continues to make and sell electronic pest control devices.
Understanding the Claims
Since the FTC has cracked down on what companies can claim about electronic pest-control devices, the companies have become very vague about what they do. Most simply claim to send out ultrasonic sounds or electromagnetic waves in your home that pests do not like. Some also say that they repel or drive pests out of your home. Since insects and rodents can be frightened by unfamiliar noises, this claim is true. The products do not (or should not) claim that it will permanently keep them out or prevent them from returning.