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Thanks Pug100.
I had looked on the Internet, (and Wikipedia), but I suppose without the exact criteria, ("electronic pest control"), I was in the wrong area.
I have purchased an electro-magnetic pest controller and I'd have to say that there hasn't been any obvious signs of mice in our house since I bought one. Neither have there been the night time noises I associate with mice.
We are currently looking after a dog who doesn't seem to be bothered in the least and we have a varied birdlife all around our home.
We did find one little mouse, not two feet from the device, a few weeks ago that had pegged it, so I have no idea why it chose to leave this mortal coil so close to a device designed to kill it. (Your comments about ultrasound and line of sight were interesting, but I checked and the device is supposed to be electro-magnetic. The device seems to conform pretty much to the description given on Wikipedia).
Iam, however, pretty sceptical and I still don't believe the device can work.
We were clearly troubled by quite a few mice in the house, (10 days in a row catching them in traps and numerous found dead by poisonening), but both the traps and poison had their drawbacks, ie the traps were cruel and frankly pretty noisy - mice tend not to die instantly and poison lead to various dead mice being found over the house. ( I thought they were supposed to get thirsty and go outside for a drink and die outside!! Obviously not true).
I was eventually nagged into getting one of these devices.
Even though there is some evidence in our home to suggest the device is effective I am waiting for the cold weather to come and see if it is still as effective. The disappearance of the mice might be coincedental.
Does any else have any other good science on these devices?