We used a similar method to Clive's to recapture the school gerbil, after it escaped and made a meal of the leads for the P A. A ramp, baited with food, led to a cardboard circle (with radial cuts) taped to the top of a plastic bucket. Miladdo was very angry when found next morning!
A good mouser is usually a well fed cat, not one on starvation diet.
My wife used to help at Cat refuge, and the rats dug their way into the pit used an indoor toilet! One of the cats then pee'd down the hole. Don't think that ratty returned, obviously got the message.
A farmers way of catching rats was to put some meal into a tall bin, and leave off the top. Each day a bowlful of meal was removed. Eventually, ratty can no longer manage to jump out. He can then be disposed of in what ever way takes your fancy. A 12 bore is likely to spread the rat and meal all over the neighbourhood though, so don't waste the meal!
Howard
Edited By Howard Lewis on 09/01/2017 17:44:01