Question

I bought one of those electronic pest repellers that you plug into the wall. After two weeks, I still have plenty of cockroaches. Do you think this one was faulty or do these things not work at all?

Answer

Scientific evidence from every research study done on these pest repellers says they are ineffective. The Environmental Protection Agency and the Federal Trade Commission say they do not work and have prosecuted some of the sellers.

These electronic devices usually amount to a plastic box that plugs into a wall. A blinking light supposedly shows you that it is “working.” The repellers are advertised by various names and with various descriptions of how they use electromagnetic waves, or ultrasonics, or high frequency sounds to drive pests away. Most insects do not have “ears” to detect ultrasonic sound. The devices do not repel cockroaches. They also don’t work against any other insects, spiders, or mice. Even so, one accommodating model has switches on the back that let you select “insects” or “rodents” and normal or “Power Boost” settings.

Look Out For These Sales Pitches for Indoor Pest Repellers:

“Magnetic pulses and ultrasonic sound immediately penetrate walls, floors and ceilings to drive pests out of hidden nests.”

“This amazing device uses your home’s existing electrical wiring to create a shifting electromagnetic field. Simultaneously, a harsh, ultrasonic siren blasts sound from the unit’s dual speakers. This sound is inaudible to humans, but it creates an incredible disturbance for pests.”

“Ultrasound cannot penetrate any solid surface (walls, floors, ceilings) or travel around corners. This is why you need a (device) for each room where you have a rodent problem.”

“Simply set the monitor for your particular nuisance. The unbearable sonic and ultrasonic sounds attack the nervous systems of common pests so that they are driven away.”

There are also personal devices that claim to use high frequency sounds to drive away mosquitoes with this faulty logic: “replicates the wingspeed sound of the male mosquito, which the biting female mosquito instinctively avoids.”

The manufacturers of these electronic pest repellers are persistent and their advertising claims are very persuasive and convincing. If only they were true. There’s no other way to say it than “buyer beware.” If you have an indoor pest problem, call a professional pest management company that has a proven track record. A reputable company won’t make false claims and will be with you until your pest problem is resolved.