Plug-in devices with big promises
Ultrasonic repellers are sold as a quiet, chemical-free answer to mice, rats, cockroaches, ants and spiders. This article summarises advice from the Committee of Advertising Practice (CAP) and the Advertising Standards Authority (ASA) on pest repellents, dated 2 February 2018, a University of Arizona Cooperative Extension publication on sonic pest repellents, revised in October 2015, and a 2021 laboratory study of ultrasonic devices and ticks published in the journal Insects. The advertising advice covers the United Kingdom. The Arizona review draws on earlier published studies and is written for a United States audience, and the tick study was carried out by researchers in Thailand and Australia. None of these sources is legal advice.
What UK advertising advice says (United Kingdom)
CAP’s advice states that the ASA, together with independent experts, has closely examined the evidence for claims made for pest repellent devices, ranging from cat-shaped metal sheets with glowing eyes to ultrasonic and electromagnetic equipment, and that it has “yet to accept any claim of efficacy”. The advice says marketers who do not hold evidence in the form of UK-based trials should not state or imply efficacy through claims, visuals or product names.
The advice adds that customer testimonials do not by themselves constitute evidence, that a product name which amounts to an efficacy claim needs a clear disclaimer, and that claims of being “pet friendly” need objective evidence. It records that in 2008 the ASA upheld a complaint about a mole product, “Anti-Mole Bulbs”, because no robust evidence of effectiveness was provided. CAP notes that its advice does not bind CAP, its advisory panels or the ASA.
What the Arizona review found (United States extension review)
The University of Arizona publication concludes that commercially available sonic pest devices for residential use have not been shown to be effective in scientific studies and that using them for common pest problems is not advised. It summarises earlier research:
- Kansas State University trials of three devices on three ant species found that none repelled ants in field and laboratory trials, although one appeared to repel them briefly in the laboratory before losing effectiveness.
- A study of nine devices on German cockroaches found no response, with equal numbers of cockroaches entering rooms with and without sound.
- Testing on four commercial devices found no effect on bed bugs.
- A study of three commercial devices found bite rates in mosquitoes increased by as much as 50 per cent when the devices were on.
- In work on rats and mice, animals showed mild aversion to ultrasound that diminished over time, which the authors describe as habituation.
The review adds that some researcher-developed devices aimed at specific species have shown promise, mostly in studies away from natural environments, but that these are not yet on the market. It also notes that dogs and other non-target mammals can hear ultrasonic sounds.
Ticks: a 2021 laboratory study (Australia and Thailand)
The 2021 study tested nine ultrasonic devices with different frequencies against female Australian paralysis ticks, Ixodes holocyclus. Each device ran for one hour with 20 ticks in a test chamber, and ten replicates were run per device. More ticks moved to the escape chamber in every test arena than in the control, and three devices differed significantly from the control. Even so, the highest proportion of ticks that escaped was only 19.5 per cent. The authors judged that amount insufficient to protect against tick bites, and said the results cannot support recommending the devices for that purpose. The work was a laboratory experiment on one species, so it does not cover other ticks or field conditions.
Reading an advert critically (United Kingdom)
CAP’s advice implies several questions for any advert. Does it cite a UK trial? Does it rely on testimonials? Does the product name itself promise a result? Does it describe the device as “friendly” to pets or other animals without objective evidence? CAP notes that no set rules exist for testing repellent devices in UK conditions and that more than one design could be acceptable, including a three-phase design of pre-treatment, treatment and post-treatment periods in which animal activity should be similar and higher in the first and last phases than in the middle one.
What tends to matter more
For readers looking for an alternative starting point, this site’s guides on pest-proofing entry points, food and moisture and on what to record when rats are suspected begin with inspection and proofing rather than a device. The Arizona review does not say sound has no role in pest management. It says the products sold for homes have not been shown to work.
Common questions
Are ultrasonic repellers banned? None of the three sources says so. The UK advice concerns what advertisers may claim.
Do they work on mice? The Arizona review describes mild aversion that faded through habituation in the study it cites.
Could a repeller harm pets? The Arizona review notes that dogs hear ultrasonic sounds. CAP’s advice says “pet friendly” claims need objective evidence.
The bottom line
UK advertising guidance says the ASA has yet to accept any efficacy claim for pest repellent devices, and a United States extension review found that commercially available sonic devices for homes have not been shown to work, with rodents habituating and no response from cockroaches, ants or bed bugs. A 2021 laboratory study of ultrasonic devices against a tick species found at most 19.5 per cent of ticks moved away. The advertising questions above and this site’s proofing guides give readers a practical way to weigh a purchase.
Sources
- Advertising Standards Authority and CAP, “Pest repellents (AdviceOnline, 2 February 2018)”
- University of Arizona Cooperative Extension (Aflitto and DeGomez), “Sonic Pest Repellents (AZ1639, revised October 2015)”
- Panthawong, Doggett and Chareonviriyaphap, Insects 2021, “The Efficacy of Ultrasonic Pest Repellent Devices against the Australian Paralysis Tick, Ixodes holocyclus (Acari: Ixodidae)”