fix your garage doors!!I understand your point; I agree that prevention is better than a cure. The problem is with the prevention, and how would I know it was working without laying traps. As long as I am catching one every couple of nights, I reckon I'm on top of it.
I have two 8' wide up and over garage doors that fail to seal at the bottom or sides. The mice can walk right in, probably without even noticing that there is supposed to be a barrier to them. The man-access door seals well, but might as well not do so. I now keep the available food source well secured, but the attraction is that the garage is warm and dry with loads of nesting material. The inside is like Steptoe's Yard so the contents provide concealment and a jungle gym for entertainment. I would never be able to keep them out or find them if I went looking. I believe that keeping on top of the problem by disposing of them as soon as they arrive is a sensible policy. I can go long spells in the Summer without catching anything, so that supports my belief that they come in for shelter not food. I live in the country so there is an abundance of food outside normally. If I start catching two mice every night, I will buy more traps and use them until the kill rate declines indicating to me that the problem is back under control.
I have no problem with mice per se; I leave alone the ones that live in the garden wall and feed from the bird table and or eat the plants now and again. They run about underneath the patio, sticking their heads up from time to time to nick some fallen morsel. The local cats tend to keep the numbers down anyway, them and the Sparrowhawk.