By Marcus Wilson 11/11/2010

I saw in the newspaper yesterday an advert for an ‘ultrasonic and electromagnetic’ mouse and rat repeller.

That got me interested. The ultrasonic bit seems to be plausible enough – I don’t know much about rodent ear physiology, but I’m willing to believe they can hear sounds at higher frequency to us and to dogs and cats (which, the advert claims, are unaffected.)  It’s the electromagnetic bit that has me interested.

A bit of googling has got me some sciency-sounding but not very useful explanations – e.g.  “The electromagnetic function uses every electrical cable in the building to carry and transmit a signal, which can be detected by the pests up to 1 metre from any cable, even inside wall and ceiling spaces”

Cables to carry electromagnetic signals? That’s perfectly reasonable – an electrical signal on your house supply is how your electricity company can switch power on and off to your hot water cylinder remotely, for one thing. But what sort of signal, and what does it do to our rodent friends, and, moreover, why doesn’t it do the same to us?

This Repeller also sends pulses through the existing wiring within the house or property and by changing the electromagnetic field, helps to create an environment within the walls, floors, and ceilings which pests would rather leave. ”

That’s slightly more informative, but still has a pseudo-science ring to it.  A bit more googling and I discover this phenomenon isn’t just used to drive out rodents.

“This aggravates the nervous system of the spiders and drives them out from their hiding places and banishes them for good”.

So we are on ‘aggravating the nervous system now’.   A quick search on ISI Web of Science for journal articles on spider, nervous system and electromagnetic waves is giving me nothing.   But what I do know is that there have been lots of studies on things like cell phones and people, which show that there isn’t much effect of EM waves on people (unless you get up to X-rays and gamma-rays), so I’m wondering why it would be different for other animals.

Anyway, to summarize, I’m intrigued.  Does anyone have ideas as to what these machines are 1. actually doing with your household wiring, and 2. what is the effect on the mouse / rat, and 3. why don’t we and cats / dogs respond in the same manner?  (Remember, it’s the electromagnetic bit I’m puzzled by, not the ultrasonic.)

0 Responses to “Electromagnetic Pest Repellent”

  • Maybe it’s combined with mouse pellets liberally laced with iron filings 🙂

  • Hmm. Spider’s don’t have much of a nervous system & I’ve never read of it being vulnerable to electromagnetic waves.

    We’ve given spiders narcotics to see what things like LSD do to web building skills (drugged spiders don’t make coherent webs) and shot them into space on the space shuttle to see what a lack of gravity does to webs.

    I’m feeling very skeptical.

  • Ditto. I had a feeling that Ben Goldacre might have done a spot of debunking of this stuff but darned if I can find it now. I’d be surprised if the machines are actually doing much of anything to the wiring & there’s no reason why rodents would be affected when bigger mammals aren’t, given we’re all wired the same way. (Sound frequencies, now that might be different.)

    • Yes, sounds like a Bad-Science thing that Ben Goldacre would pick up on – if he has, I haven’t seen it. I’m tempted to buy one and get an electronics student to pull it apart and find out what it’s doing (if anything).

  • If the pulses are going through your house wiring, what’s to stop them travelling out to the street and into next door’s house wiring, klling your neighbour’s valuable pet spider collection?

  • There are devices out there that seem to work very well to repell small insects, ants in particular. These are ultrasonic and make no claim regarding magnetism in any form. This is good as radiated magnetism can be harmful to human health, whereas ultrasonics have yet to be found to cause any harm to humans. I suggest that a search of “pest repeller” on trademe could be enlightening

    • Maybe I should try one. Ants in the house are a real annoyance at the moment. Unlike rodents, the cat doesn’t catch them for you. You say ‘radiated magnetism can be harmful to human health’. The effect of electromagnetic waves and health has been much studied (though in many cases it is a really hard study to do well – e.g. people who live under power lines tend to have low incomes – because the house is cheaper under the power line – and low income leads to health issues in other ways). Unless we are talking very high frequency waves (e.g. sunburn due to u.v., or Xray and gamma ray damage) there is no clear evidence of long-term health issues – at least not that I’m aware of. N.B. If magnetism is being radiated, then electric fields are also being radiated – the two travel together – so you have an electromagnetic wave.

  • This should help with what seems to have been false claims at an unreasonable price. Please check it out!

    Complaint about rodent repeller upheld
    Home » News » National
    Thu, 12 Jan 2012
    News: National
    A television advertisement for an ultrasound mice and rat repeller is one of 280 complaints to the Advertising Standards Authority last year about misleading products.
    The advertisement for Pestrol Rodent Free pest control device, which showed rats and mice gnawing at wood and chewing on electrical cords, promised to rid customers “dirty unwanted intruders” using electromagnetic pulses.
    However, the advertiser Lifestyle Logic Ltd could not substantiate the claims and was therefore misleading, the ASA ruled.
    Of the 280 complaints, 73 were upheld or settled – after the advertiser admitted fault, said ASA chief executive Hilary Souter.
    Complaints about truthfulness or overstatement in advertising were “quite common”, she said.
    “Under our system if you make a claim and it is challenged through a complaint to us the advertiser needs to substantiate the claim. If they can’t they will be in breach of the Act.”
    Other complaints upheld against products included Quantium Solutions for weight loss patches and male arousal patches that were not supported by research and a Goldair heater that took the chill of the air but failed to heat rooms as claimed.
    The pest control advertisement said the product used “ultrasonic sound waves pressure them (pests) to leave”.
    However, B. Clark objected to the advertisement “on the grounds that it is not a truthful presentation of the products capability”.
    The complainant found the company’s claims about how the product worked using electromagnetic pulses and ultrasonic sound waves misleading.
    “I suggest the above statement has no basis in science or reality when applied to this product.”
    The advertiser Lifestyle Logic Ltd argued that the rodent repeller combined electromagnetic and ultrasound technology and was used to rid areas of rats and mice in the walls, ceilings and open spaces.
    “Based on the information and feedback received from a wide range of customers the Pestrol 4 in S Rat and Mice Repeller is performing extremely well and taking care of the tasks it was advertised to do,” said the company.
    The return rate on the product was also “close to zero”, it said.
    However the Complaints Board said the the advertisement was was in breach of Rule 2 of the Code of Ethics because it was misleading as the claims made could not be substantiated.
    Onscreen statements for the advertisement said it was ‘proven technology to drive mice and rats away’ and was ‘guaranteed to work’.
    The Complaints Board said the advertiser provided no evidence of testing or research to prove the claims, and was therefore “likely to mislead or deceive the consumer”.
    It was also in breach of Basic Principle 4 of the Code of Ethics as the advertisement had not been prepared with the due sense of responsibility to consumers, said the Board.
    Commission spokesman Greg Allan advised customers to research a product first to make sure they were getting what they paid for.
    He suggested researching the product online to see if others have complained about it, if possible, check the claims it’s making and ask the retailer questions before handing over your money.

    • How interesting – particularly how the Complaints Board has taken a very scientific approach and asked for the evidence to support the claims – and there being none dismissed this product as likely to be misleading.

  • When rats were attacked my house, I decided to use electronic repellers. Firstly, it’s really works. Secondly, I don’t want to see any corpse in my garden. I have young daughter, and she can be afraid. It’s a great amount of different repellers in the store. I read this guide about “How to choose the best electronic repeller” Finally, rodents left my home.

    • Was it the ultrasonic repeller that did the repelling? When a rat (and a few mice) invaded my garage, I simply carefully went round and removed all the food items (there was a large bag of old catfood sitting on the back of a shelf which we’d forgotten about after our cat died.) That did the trick, too.

  • Thanks for this info, Marcus. I have never seen any evidence offered that these devices work, in fact everything I’ve ever read dismisses these as having no scientific validity.
    However, we were being driven nuts by rats in the ceiling of a holiday house. In desperation we bought one of these devices (we would have tried voodoo, anything to drive them away & stop the noise) and the rats left. Maybe they didn’t like us either.
    Would love someone to do a proper study on these devices before I weaken and buy another one next winter.

    • I’d predict that the statements on these comments which support the device are nothing more than marketing trolls. I have one of these things and the rat in my house seemed to go crazy for a few days after I bought it but is now settled back into its regular activities. Is it the ionized air the device produces? Or the electromagnetic Pulse? Based on the fact the rat is still my roof, I’d be willing to be all of the effects thus far are due to my having paid inordinate attention to the activity of the rat rather than its habits actually changing. Until it’s gone from my residence, I’m not convinced.

  • these things do not work at all and this company is dishonest and iwod avoid any dealings with them at all. mr John fenning has a history with commerce commission. avoid them at all cost

  • @Marcus Wilson – old thread – Re the comment about no clear evidence of harmful effects to health from “radiated magnetism”: I wonder if you’re ruling out microwave ovens, for instance, which can use electromagnetic radiation at 915 MHz or 2.45 GHz… And according to Wikipedia, Westinghouse used 60 MHz in a demonstration in 1933 (…

  • These devices absolutely work to drive rodents out of walls where they nest so they can be trapped. You still need traditional snap traps though.