I have used friendly traps, however they require some skill to get an air rifle headshot, I have shot them too.
However recently I have started using fenns. I made a simple tunnel box with two small holes. Nothing other than a grey or rat can enter. It's easy to check and is labelled traps inside as a warning with two bricks on top. Two traps are in the box either side adjacent to the hole.
The box is long enough so that a cat or similar cannot paw the trap trigger at all