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A couple times I've seen advertised on TV and in supermarkets electronic devices that allegedly irritate all sort of insects and rodents, such as mosquitoes, mice, and rats, forcing them away from the ultrasonic sound or other emissions of the device.

Is there any scientific basis behind these products?

Is there any evidence that these products repel pests?

Related: Do ultrasonic cat repellents work?

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    Anecdotally, I just bought one of those as a joke last night. It proved to be just that, a joke. – Monkey Tuesday Jul 03 '11 at 19:23
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    it's not **radio frequency**, it's **ultrasound** – vartec Jul 03 '11 at 22:21
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    Anecdotally, we installed an ultrasound rat repellent. Almost every other day we discovered a dead rat caught in the trap near it. So I guess you could say it was effective at luring in rats, if you assume correlation = causation. – Thomas O Jul 03 '11 at 23:06
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    they sure don't seem to work for mosquitos. But I'd love to see some real data. – Monkey Tuesday Jul 04 '11 at 00:42
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    The basis of these devices is that most of these pests can hear sounds in the range of these devices. Whether the sound they emit annoys the pests is the real question - but there's a "scientific basis" behind the "theory" of these devices. I'd like to see the second question answered with studies... – Adam Davis Jul 06 '11 at 17:05
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    Note the related cat question where they have some effect, which suggests they may affect other mammals too. While researching that I also saw studies into ultrasonic deterrents on badgers and dingos, but didn't see the outcome. – Oddthinking Aug 29 '11 at 07:41

2 Answers2

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Not effective against mosquitoes:

Electronic Mosquito Repellents Don't Work, Say Researchers

Study investigators had counted mosquitoes landing on bare body parts — mostly arms, legs and feet — during specified time periods in which an EMR was switched on or off.

There were no significant differences in the landing rates with and without EMR, making the devices ineffective for preventing malaria transmission.

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  • personal experience however seems to indicate they do work. As a kid (when we lived in an area with lots of mozzies) I was stung a lot more often when not using one as compared to when I was using one. Of course not enough datapoints to make it a viable study, as there could very well be other factors involved, but it's interesting :) – jwenting Aug 30 '11 at 05:43
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    @jwenting: Do you remember what kind it was? Was it ultrasound, or with a refillable chemical compound? (The chemical ones are also plugged into electricity, which is used to vaporize the compund). – Suma Aug 30 '11 at 07:44
  • it was ultrasound. Device was just a small speaker with a single AA size battery and a switch (and a few components to drive the speaker, obviously). Made a barely audible buzzing sound when turned on. – jwenting Sep 05 '11 at 07:38
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In addition to the study above, the Federal Trade Commission (in 2001) warned manufacturers of these devices that they needed to support their claims with evidence in order to continue to sell the devices. They had specific claims that they found to be problematic, and also indicated that the idea of ultrasonic devices was problematic:

These are the claims that the FTC wanted the manufacturers to substantiate:

Eliminates rodent infestations;
Repels insects;
Serves as an effective alternative to conventional pest-control products;
Increases or assists the effectiveness of other pest-control methods;
Eliminates fleas on dogs or cats; and
Scientific tests prove product effectiveness.

Prior FTC complaints alleged that any reaction by rodents to ultrasound would be temporary at best because rodents become accustomed to ultrasound and will return to their nesting or feeding areas even in the presence of an ultrasonic device. Furthermore, previous FTC complaints alleged that ultrasound devices do not control insects.

In 2002, Lentek International was charged by the FTC with making false and unsubstantiated claims about their pest-control products. In 2003, Global Instruments settled with the FTC. The settlement prohibited them making their claims about the devices unless they came up with substantiating evidence.

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