Thousands of Indians die of snakebite every year, and we kill many more snakes in fear and retribution. Activists have struggled for years to help both people and snakes without loss of life. A Karnataka-based company called Prasadam Industries claims to have hit upon the solution. It has developed a souped-up walking stick that it describes as “a Solar-Powered, ultrasonic rodent repeller that emits ultrasonic sound waves designed to keep snakes at least 50 metres away.” Currently farmers get it for free, but the company plans to sell it from the end of July onwards.
A slickly produced video is popular on social media. Some in the media appear to have accepted the sales pitch at face value. An old saying applies here for them: if it — in this case the anti-snake device — sounds too good to be true, it is.
Frequencies above 20kHz are ultrasonic, but snakes sense low frequency sounds of less than 1kHz. No species of serpent is known to hear high frequencies. In 2001, the Federal Trade Commission of the U.S. said that there was nothing to show that ultrasonic deterrent devices keep away insects, rodents or any other animal pests. It warned manufacturers to back up their claims with scientific evidence. If rodents that can hear ultrasonic frequencies aren’t repelled by them, what are the chances that these frequencies chase away snakes?
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When challenged, the administrator of the Prasadam Industries page on Facebook (FB) replied, “It isn’t ultrasonic sounds but rather vibration pulses that are felt by the serpents in its vicinity... our equivalent of a hangover headache.” Subsequent publications say that the gadget emits “seismic pulses”. However, the FB page and the narration in their video continue to say it produces ultrasonic waves. No field trials or demonstration are available for analysis.
Ashleigh Wolfe of Curtin University, Western Australia, studied the effectiveness of snake deterrents, including two vibrating devices, and found them wanting. “Snakes are often found in industrial areas, warehouses, and basking on the sides of roads where there are lots of very loud and constant vibrations,” she says. They aren’t put off by ground tremors from large machinery and heavy vehicles that could potentially kill them. How would a small monotonously repetitive device then work against them?
The device is not benign in its ineffectiveness; it can cause real harm. The advice offered by conservationists and activists on how to reduce contact with snakes include carrying a torch at night and wearing footwear. If farmers believe that merely setting down a device would scare away snakes, they gain a false sense of security. They won’t take the necessary precautions and this will lead to more bites. Such gadgets offering shortcuts to safety don’t do any good for either humans or snakes.
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The writer is a freelance journalist specialising in wildlife science and conservation practice in India