I had a neutered male cat who was a great mouser. If there was one in the house, which was rare, then he got it. A neutered female I had wasn't interested. Impossible to know if your cat will be a good mouser, but getting one from a farm background would be a good idea. No cat now, and I've had on and off again mice problems. With an old Victorian house they can come in from next door by way of the floorboards. A friend of mine lives in an old farmhouse out in the country, has indoor and outdoor barn cats and still has a mouse problem in her house. She hears them in the walls!