Ultrasonic Pest Repellers: Solution or Scam?

Ultrasonic pest repellers are electronic devices that emit high-frequency sounds designed

to repel, injure or kill household pests, such as rodents and insects. Whether they're actually

effective at doing so has been disputed by testing labs and the U.S. Federal Trade Commission (FTC).

Left unchecked, rodents and insects can transmit salmonella, hantavirus and other diseases,

as well as cause significant building damage. Signs of a rodent infestation include droppings,

especially near food and beneath sinks, gnawed or chewed food packages, and holes in structural

materials that can provide entry into the home.

Cockroach infestation, which is arguably the most pervasive and hard-to-eliminate type of pest

infestation, especially in urban areas and industrial and commercial kitchens, is evidenced by the

pest's droppings, which are pepper-like specs, typically found in kitchen cupboards, as well as their

egg sacs, which are often spotted in hard-to-reach locations, such as cracks and crevices in kitchen

cabinets and drains, and behind dishwashers and refrigerators. Ultrasonic pest repellers are claimed

to eliminate even these types of household pests.

How They Work

The use of audible sound to deter pests is an old strategy; the ancient Chinese used a

number of mechanically operated sensory-repellent devices to deter rodent infestations

in agricultural crops and buildings. Ultrasound, which is defined by sound frequencies beyond

the upper limit of human hearing, has been used as pest control only over the past few decades,

however.

The 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 and allegedly eliminate the need for traps and poison, which are thought by some

to be inhumane forms of pest control. Electromagnetic and subsonic devices are also available, and

all designs vary by signal intensity, rate and frequency.