Ultrasonic Devices and Deer Whistles: Do They Work?
Noel Mues, Extension Educator
University of Nebraska-Lincoln Extension
It is ingrained in the human condition to find easier ways to do things. It is the reason why people buy ultrasonic devices. These devices have existed for many years and are marketed through mail-order companies, home shopping cable channels and gardening magazines. They are readily being sold on the Internet and at hardware and other stores.
Manufacturers claim these devices use ultra-high frequency sound waves to chase away pests, from rodents to spiders. But, do they work?
Insect pests – A nicely written fact sheet from Dini Miller and Phil Koehler (2009), called Least Toxic Cockroach Control has this to say. “Ultrasonic devices are frequently advertised as a non-toxic method of cockroach control. However, extensive research has shown that these devices neither kill nor repel cockroaches.”
Other research has shown ultrasonic collars do not drive fleas off cats and dogs or change flea activity patterns. And, ultrasonic bracelets do not repel mosquitoes or change mosquito behavior.
Wildlife – A number of research publications, whose authors looked at the effectiveness of these devices on wildlife, have this to say. “There is no evidence that ultrasonic devices are effective at repelling or deterring wildlife pests.”
Researchers found they did not repel wildlife, including rats and mice, white-tailed deer, bats, cats, starlings, pigeons and other bird species.
Why don’t these devices work? – Many animals hear in the same range humans do. Others may hear higher frequencies, but may not be highly irritated by the sound. Even if they can hear the ultrasound frequency, animals readily become habituated to repeated sounds. They quickly learn the ultrasound isn't dangerous and return to their normal activities.
Another reason ultrasonic frequencies don’t work is they are very weak and drop off rapidly with distance from the source. Half the energy of ultrasound produced is gone at 15 feet, and no energy remains at 30 feet. Ultrasound is blocked by objects like walls and furniture and it can’t travel through walls and around corners.
It is possible for ultrasound to cause convulsions and permanent damage, but the sound intensity must be so great it would also damage humans and domestic animals. Commercial ultrasonic pest control devices do not produce sounds of this intensity.
Why are these devices still being marketed? – The FTC has repeatedly gone after the companies that manufacture these devices. The companies are shut down, but the company changes the ultrasonic frequency and begins selling them again. If only people stopped buying these devices, companies would stop selling them.
There are plenty of non-toxic or low-toxic methods to keep pests outside, but admittedly, they take more work. To keep mice and invading insects out, seal cracks and crevices and eliminate weedy growth or vegetation near the house.
Deer whistles – Here is information about another type of “sound” repeller - the deer whistle. Many people have purchased these devices, which are mounted on the front of the car or truck. Air rushing through the whistle is supposed to make a sound which alerts animals and keeps them from crossing the road, hence preventing deer-car accidents.
Do they work? Not likely. A
It is possible for a deer to hear the 3 kHz signal, but the sound is drowned out by the road noise created by the car. Some whistle manufacturers claim deer can hear the sound a quarter mile away, but this has not been verified by research.
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So, if you’ve got a deer whistle on your car or truck, don’t count on it very much to keep the deer on the side of the road. Your best protection is to drive carefully, especially at sunrise and sunset when deer are hard to see. And, if you see one deer, slow down…there will often be another deer nearby.
Source: Acreage Newsletter Barb Ogg, UNL Extension Educator,
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