Good mouser cats are priceless if you live out in the wilds, a particularly efficient killer we had took:
Entire nest of rats (which were found the next morning piled up next to nest entrance)
A chicken (kept quiet about that)
Cock pheasant (one wing inside the cat flap, rest of the bird on the outside where he’d tried to pull it in)
Wood pigeons
But his favourite were rabbits from the woods. Oddly it was only the ears and heads that would be eaten. Not pleasant hearing the crunching sound coming from behind the sofa! Never bothered to catch anything small though that one, must’ve enjoyed a challenge.
Don’t put poison down if you have cats though. There is a chance they may catch a poisoned mouse even if the poison itself is inaccessible to them.