Ultrasound is a sonic wavelength that is higher than most humans can hear typically above 20 kHz in frequency. Ultrasound is often touted as a method of effective pest control. But is it? Before I answer that question, readers should understand that ultrasound is just one category within the larger category of sound-based or audible frightening devices. Frightening devices are categorized into visual, audible, visual-audible, and biological sections. Within the audible frightening device categories, sound-based devices can be further broken down into categories of pain-inducing sound, bioacoustics (i.e. sound made by predators that evokes a fear response in an animal), non-biosonic devices (i.e. those that just create an irritating noise), jamming communication (i.e. sounds that prevent animals from sound-based communication) and finally ultrasound. (I wish to credit Bomford, Mary and Peter H. O’Brien. “Sonic Deterrents in Animal Damage Control: A Review of Device Tests and Effectiveness.” Wildlife Society Bulletin 18 (1990): 411-22 for these categories and much of the information on ultrasound being shared here).
Bomford and O’Brien surveyed the literature on the efficacy of ultrasound to manage pests. Their findings were not heartening. First, they noted that the research showed no effect on insects. Ultrasound did not show any practical effect on birds. But what about animals that are capable of hearing in the ultrasonic range such as bats and rodents? Tests using ultrasound on bats were also inconclusive. But the research on rodents, like rats and mice, did find some effect. But the effect was temporary and only effective for short distances. What was the effect? It was that rodents showed some avoidance of areas where the sound was present. By the way, other studies reviewed by the authors came to more negative results, meaning they didn’t think ultrasound had any practical use for rodent control.
So, in light of this general lack of supporting evidence, why do people still rely on ultrasound as pest control device? I think possible reasons include: 1. The tendency to trust “experts” concerning subjects that are not familiar to us, 2. The wishful desire for ultrasound to work because of its ease of use and the fact it would be silent as far as human ears were concerned, 3. Ultrasound’s low cost and chemical-free solution, and 4. The belief that earlier technology can be superseded by newer technology.
What should you do? I recommend that people save their money. But if you are determined to try ultrasonic devices out, don’t be surprised if your results are less than favorable. If you have positive results, I would love to hear from you.Stephen M. Vantassel, CWCP, ACE, is the owner of Wildlife Control Consultant, LLC. He helps people restore their balance with nature through publishing, training, consulting, and the internet. He has published numerous articles in trade and academic publications along with several books (http://kingsdivinity.academia.edu/StephenMVantassel). He is a sought after speaker and trainer. Copyright All postings are the property of Stephen M. Vantassel and Wildlife Control Consultant, LLC. Text (not images) may be reprinted in non-profit publications provided that the author and website URL is included. If images wish to be used, explicit and written permission must be obtained from Wildlife Control Consultant, LLC.