I hate to kill the sweet little furry rodents too. I've lived in the same house since 1980 and never seen any mice here until about 3 years ago. My cats would sometimes make presents of dead ones, but about 3 yr. ago, I rescued a couple of voles (pretty sure they were voles, not mice) who were being tortuosly toyed with by my calico kitty, and I got a terrarium for them to live in. It was fun watching them romp on their wheel, etc.
But one day, when I was cleaning their living space, one escaped. (The other died rather unexpectedly when I was away for about a week, despite my having left enough water and, I think, enough food for that time.
I've always wondered if the infestation I've seen over the past 2-3 years has stemmed from that one vole/mouse— the one I rescued from my housemoggie several years ago.
As much as I empathize wi' th' eee, sleekit cow'rin' tim'rous beasties, there's come a point where it has to be me (able to breathe and not be ill) v. them.
i've tried some "humane" traps - only to find a wee mousie dead within, probably having bit the dust after days of dehydration - and some snap traps, which probably in most cases (sad to say, maybe not all) dispatched the wee furry beastie forthwith.
If I can find a feasible way to spare the wee cow'rin' tim'rous beasties yet maintain liveable premises within my own house, I'm very much open to such information.
But for now, I'm afraid I must go with one of the less Idealistic solutions
I really wish that were not so.