My daughter moved into a very old house that had been updated. She has two cats, the female is a neurotic paranoid witch that seems friendly until she realizes you're a stranger, then she attacks. After moving in they realized they might have mice. Then psycho kitty confirmed it.... by killing said mousies. So psycho kitty has earned her keep, but she still gets shut in a bedroom when visitors come over.
This winter I found out that Raz knows how to mouse. I found this out when a field mouse got in through the cellar hatch and he brought it upstairs and dropped it in front of my chair - that I was sitting in.
The mouse was alive. It ran under the chair.
The other two kitties were really entranced (Heath and Rainey) but hadn't one clue what to do.
Thankfully Raz did handle the issue.
I was told that mousing ability is dependent on whether the cat was taught to do so by it's mother - if they weren't with Mom long enough they don't learn.
Good luck! There's always Havaheart!