>>But how do you get rid of critters who will eat about anything?
>
>They will chew on anything but they can't live on it. If you leave crumbs about etc mice will live on it.
>Rat love compost heaps so if you compost your waste you need to make it rat proof. Or ignore the rats. They've never bothered me provided they aren't running round the house.

And as long as your walls are well plugged, or (much better) solid, not hollow, they can stay outside.

We had a problem with some kind of priest two doors down the street, who'd frequently bring the extra bread from somewhere, and would throw the slices to seagulls in the back alley. These were too large for seagulls to carry, but they have birds' brains so they try anyway. Pieces would fall in our patios, and the seagulls don't venture into such tight spaces. But the rats do. And our first neighbor built a deck, covering all the patio. My bet is there was a rat's nest there. In winter 08/09, we caught about a dozen, then next winter none. They either got smart or moved to greener pastures.