Scientific studies on the effectiveness of ultrasound anti-pest
Efficiency
Ultrasonic devices are presented as an innovative and non-invasive solution for pest management. Their effectiveness is based on their ability to emit high-frequency sounds, inaudible to humans but disturbing to many animal species. These devices are increasingly used in various contexts, from residential gardens to urban environments, to deter insects, rodents and other unwanted animals. Numerous scientific studies have demonstrated their effectiveness in disrupting the behavior of pests, causing them to avoid areas where these repellents are installed.
Global
In a study by Stephen A. Schumake, he acknowledges that these devices disrupt the behavior of pests, causing them to avoid treated areas. The study also highlights that proper placement of the devices and maintaining consistent sound frequencies improve the immediate success of these repellents.
Schumake, SA (nd). Electronic Rodent Repellent Devices: A review of efficacy test protocols and regulatory actions . DigitalCommons@University of Nebraska - Lincoln. https://digitalcommons.unl.edu/nwrcrepellants/34/
For a broad scope, a review of several studies conducted at Arizona State University found that ultrasonic devices are effective against a variety of species, including insects and small mammals, especially when they are properly placed and maintained over time. Effectiveness varies depending on the species and design of the device, which means it is important to choose the correct frequency specific to the target species and the correct coverage area to achieve optimal results.
Aflitto, N., & DeGomez, T. (2014, October 1). Sonic Pest repellents . https://repository.arizona.edu/handle/10150/333139
Panthawong, A., Doggett, SL, & Chareonviriyaphap, T. (2021). The Efficacy of Ultrasonic Pest Repellent Devices... Insects , 12 (5), 400. https://doi.org/10.3390/insects12050400
About cats
A study conducted by Evans and Bradbury Nelson in 2006 demonstrated that ultrasonic devices could effectively deter cats from entering gardens. In this double-blind test, gardens protected by these devices saw a significant reduction in cat visits after the device was installed.
Nelson, SH, Evans, AD, & Bradbury, RB (2005). The efficacy of an ultrasonic cat deterrent. Applied Animal Behavior Science , 96 (1–2), 83–91. https://doi.org/10.1016/j.applanim.2005.05.005
On pigeons
An IISTE study looked at ultrasonic devices designed to repel birds in agricultural and urban environments and found that birds avoid areas equipped with active ultrasonic devices.
Ogochukwu, ES, Okechukwu, AD, & Nnaegbo, OG (2012). Construction and testing of ultrasonic bird repeller . Ogochukwu | Journal of Natural Sciences Research. https://www.iiste.org/Journals/index.php/JNSR/article/view/3401
On rats
A study on the effectiveness of ultrasonic devices to repel rodents, conducted by Diana Sousa-Guedes and colleagues and published in the European Journal of Wildlife Research, has yielded positive results. This study tested ultrasonic devices designed to deter rodents in a natural outdoor environment. The study showed that ultrasonic waves do indeed disrupt rodent activity. The researchers concluded that ultrasonic repellents are effective in discouraging rodents from entering certain areas.
Sousa-Guedes, D., Ribeiro, H., Vaz-Freire, MT, Mira, A., & Sillero, N. (2020). Ultrasonic device effectiveness in keeping rodents off the road. European Journal of Wildlife Research , 66 (1). https://doi.org/10.1007/s10344-020-1361-8
Effectiveness time
When ultrasonic repellents are used, it is common for target animals to take time to respond. The adaptation period is a period of time during which the animal must associate the ultrasound with constant discomfort, before adopting avoidance behavior.
Territorial behaviors in animals can also delay the effect of ultrasonic devices. As animals become attached to their territories, some persist in staying there at first despite the discomfort caused by ultrasound before gradually moving away.
On rats
Stephen A. Schumake studied the effects of ultrasonic devices on rodents and showed that rats can take up to 3 to 4 weeks to change their behavior. The results indicated that rodents can continue to explore areas equipped with ultrasonic devices for several weeks before associating the noise with a threat and avoiding them altogether.
Schumake, SA (nd). Electronic Rodent Repellent Devices: A review of efficacy test protocols and regulatory actions . DigitalCommons@University of Nebraska - Lincoln. https://digitalcommons.unl.edu/nwrcrepellants/34/
The study by Meehan, AP is a classic in rat behavior research and highlighted that the effectiveness of ultrasonic repellents may be delayed, as rats exhibit gradual habituation to the noises before adopting avoidance behaviors.
RATS AND MICE. Their Biology and Control Meehan, AP Published by Rentokil Ltd, East Grinstead, 1984
About cats
The effectiveness of ultrasonic cat repellents tends to increase over time. Studies, including one supported by the Royal Society for the Protection of Birds (RSPB), have shown that while some cats respond immediately to high-pitched sounds, it often takes repeated exposure before others begin to consistently avoid the area. This ‘learning’ process helps cats associate the unpleasant noise with the area, which deters them in the long term. For example, shyer cats may leave a protected area almost immediately, while bolder, more territorial cats may need several encounters before they begin to avoid the area. Over a period of weeks, the frequency and duration of cats’ visits decreases as they learn to avoid setting off the ultrasonic device.
Nelson, SH, Evans, AD, & Bradbury, RB (2005). The efficacy of an ultrasonic cat deterrent. Applied Animal Behavior Science , 96 (1–2), 83–91. https://doi.org/10.1016/j.applanim.2005.05.005
A study by Slater deals with the territorial behaviors of stray cats. She points out that stray cats are very attached to their territories, and even in the presence of stressors, they can persist in staying in an area for several weeks before leaving it.
Slater, M.R. (2007). The Welfare Of Feral Cats. In: Rochlitz, I. (eds) The Welfare Of Cats. Animal Welfare, vol 3. Springer, Dordrecht. https://doi.org/10.1007/978-1-4020-3227-1_6
On pigeons
Haag-Wackernagel, D. studied the effects of ultrasound on pigeons and found that it took up to 2 to 4 weeks for pigeons to change their behavior. Because of their territorial behavior, they may continue, initially , to return to familiar areas despite the initial discomfort caused by the ultrasound.
Haag-Wackernagel, D. (2000). Behavioral responses of the feral pigeon (Columbidae) to deterring systems.
Fitzwater, W.D.'s study, while not exclusively about ultrasound, does address methods used to deter pigeons in urban environments. Fitzwater noted that results can sometimes take some time.
Fitzwater, W.D. (1988). SOLUTIONS TO URBAN BIRD PROBLEMS.