Your ultrasonic thing sounds like that barbaric device they've started using to disperse teenagers who hang around park benches, off-licences etc. My fury over the latter - and reading Daniel Lord Smail's 'On the Brain and Deep History' makes me seriously question my double standards where other mammals are concerned!
(And my mother used to say I ate soap when I was a toddler - what does all this mean? Anything? Probably nothing.)

Been there, and there's only one answer - Traps.
But there are ways of not taking life. Have you googled "Humane Mouse Traps"?
There seems to be lots about.

Get with the blog, Paul - Rob already tried humane traps. :)

There is *nothing* that rodents won't eat. We have holes in our walls, curtains, dining table etc to prove this. I don't know about the ultrasonic things; we haven't tried one, since our rodents are our pet rats ;-)

I think your only chance is to find the point of ingress & block it. If there's a decent sized family, catching the odd one and taking it for a trip in the country isn't really going to solve it.

There is one very simple answer - its called a cat. Then instead of having a small furry someone eat your soap you can have a slightly bigger furry someone to eat your breakfast while you are still eating it, pounce on your chest in the middle of the night, leave rabbit entrails and mice gall bladders in the hall.. its the obvious answer. But you know this already so why the prevarication?

I used to be very into humane traps until one night last year, I was up at some ungodly hour feeding Timothy his bottle, and a mouse ran across the living room floor and across his play gym.

In my sleep-deprived state this seriously freaked me out and since then I have used simple, B&Q traps smeared with peanut butter. It's devastatingly effective.

We live relatively close to the river here in Abingdon, and we have had something of an infestation. I've got a bit medieval on their asses (to borrow a phrase) and I don't feel entirely good about it - but in the last 6 months I've trapped over a dozen mice. With a baby in the house, I'm afraid the niceities of trying to trap them humanely have gone out of the window.

This makes me a bad man I realise. But I've shared my experiences just in case you wanted to feel better about any upcoming big decisions you need to make on this issue...

If you don’t want the commitment of a cat, sometimes you can get rid of mice by using things that smell of cat. Borrow some cat bedding, or fur combings from the nearest handy cat person (Emma?) and leave them strategically placed in the mouse runs.

Sarah, maybe this thing only works on teenage mice. That would explain why the rest are ignoring it.

Paul and Katherine, I've only got one humane trap; I'm going to try others, maybe different types. They seem ready to investigate anything except this trap.

Judith and Dee, I am a bit wary of getting a cat (even though I love having them around) because it means never being away for more than about 48 hours, without making elaborate plans. (And Dee, I let next doors' very friendly cat in, but he tried to mark the place. So when I'd finished cleaning up after him, I put the paper towel near where I thought the mice were getting in. It doesn't seem to have helped.)

Mark, they are sort of backing me into a corner. But I'm going to resist actually killing them for a while yet. Though they seem to be trying to goad me into it.

And thanks all for taking such an interest.

I'm afraid you are going to have to kill them. As much as you would like to be humane and let them loose in the countryside, don't. They will just come back.

We had mice for a while and tried everything - we really tried to be nice! But in the end, the only thing that got rid of them for any length of time was a visit from the pest control man at the council.

Remember everyone, it was Katie from Ebury who said I should kill them. I'm just obeying orders.

Seriously, though, I'm going to hold out a bit longer, but they don't make it easy. They're mad for soap right now so it would be a cinch to poison them and ridiculously easy to squish them in a trap. Whereas all the non-lethal things so far have done nothing. I just don't want to kill them. (Plus it's narratively not a good conclusion to this saga.) But if they carry on getting bolder and more destructive (and depriving me of sleep) I suppose they might eventually erode my last bit of sympathy for them.

I have to say, trying to catch the mouse was pretty fun for a while. I felt like Wiley Coyote setting Roadrunner traps.