How Does an Electronic Rodent Deterrent Work?

Ultrasonic Devices

One type of electronic rodent deterrent uses ultrasonic waves. These types of devices use very high-pitch sound waves. These waves are designed to be inaudible to the human ear, but can be heard by mice and other rodents. The idea is that if these sounds are very loud, they will cause rodents to become uncomfortable and avoid the area. Of course, these sound waves can only cover a certain amount of area. As a result, several of these devices may be needed for a large space, and these sound waves will have a hard time penetrating solid surfaces, so rodents may still escape them by going into walls and cupboards.

Electromagentic Devices

Some electronic rodent deterrents use electromagnetic waves as well as ultrasonic sound waves. When plugged in, these devices send electronic pulses through a house's wiring. It is thought that the electromagnetic waves from these pulses of electricity affect the nervous systems of rodents, causing them extreme discomfort. One advantage of this type of device is that it sends the signal through all of the wires, which allows it to drive rodents away from the interior of walls.

How Effective are These Devices?

In most cases, the evidence that supports the use of ultrasonic and/or electromagnetic electronic rodent deterrents is anecdotal. Some people claim that they are very effective, whereas others have found little or no benefit from them. When tested, many commercially available ultrasonic deterrents have been shown to be able to cause rodents to avoid the area around the device for a period of time. However, these tests have also found that over time, the rodents return to the area. The length of time for which this sort of device is effective has been found to depend on the type of ultrasonic wave as well as its intensity.