You need 60% (at least) Terrier - Jack Russell or better still, Staffordshire. Fox terrier is also good but I would be wary of Yorkshire.
Best Ratting Formula

Well, they could always get more mice, which should then attract some owls.
If you want the owls to stay, you will constantly have to replenish the mice.
And I am wary of Yorkshire, they talk funny.

A boa might handle the 'roos but I think it with struggle with small vermin.

You need 60% (at least) Terrier - Jack Russell or better still, Staffordshire. Fox terrier is also good but I would be wary of Yorkshire.
Is there any genuine science behind this?

Don't trouble yourself; you've got an honest face.
I didn't think linking to individual posts worked.

How about pans of instant potatos laying around, then when they drink water they'll swell up and die. (Or was that an old wive's tale?)

How about pans of instant potatos laying around, then when they drink water they'll swell up and die. (Or was that an old wive's tale?)
Maybe after eating the instant potato, they'll lose the will to live anyway.

Other than cats that are the best predators for mice, you can go with an owl, an hawk, a snake or a mouse trap.
The traps are very cheap but the cheese is now so expensive. I think that what comes next is a research on the best mouse trap cheese at the cheapest price.
The cheapest way to buy cheese is in bulk, then you have to store it somewhere. If you're not very careful, that could attract vermin.

I haven't encountered Twin Peaks yet. I'm waiting for it to be broadcast on the wireless.

What is this "wireless" of which you speak? We await it's invention.
If you think that sounds great, wait until you see the "talkies".

One point on which there seems almost universal agreement:
"The female of the species is more deadly than the male."

Some exotic breeds have been suggested:
Mini Foxie
Manchester ELO Terrier
Tenterfield Terrier
Cairn or a Norwich Terrier
min pins (miniature pinscher)
Glicko x dachshund
finnish lappies (lapphund)
Does anyone have any experience of these? I've never even heard of half of them!

I'd want to avoid one like this ...
``We will not have him put down. Lucky is basically a damn good guide dog,'' Ernst Gerber, a dog trainer from Wuppertal told reporters. ``He just needs a little brush-up on some elementary skills, that's all.''
Gerber admitted to the press conference that Lucky, a German shepherd guide-dog for the blind, had so far been responsible for the deaths of all four of his previous owners. ``I admit it's not an impressive record on paper. He led his first owner in front of a bus, and the second off the end of a pier. He actually pushed his third owner off a railway platform just as the Cologne to Frankfurt express was approaching and he walked his fourth owner into heavy traffic, before abandoning him and running away to safety. But, apart from epileptic fits, he has a lovely temperament. And guide dogs are difficult to train these days.''
Asked if Lucky's fifth owner would be told about his previous record, Gerber replied: ``No. It would make them nervous, and would make Lucky nervous. And when Lucky gets nervous he's liable to do something silly.''
[Source: Europa Times, October, 1993]
Hi I have some friends with a small property (5 acres) in the Adelaide hills and they are overrun with mice.
They don't want to use poisons and aren't into cats.
So what is the best breed or breeds to catch mice?. They already own an old deerhound who enjoys watching the mice run around her