My cat has caught two mice to date. Both were inside my apartment; however, both times were on a day after I had fallen asleep and left the window open all night for her (and anything else, apparently) to come in and out. Boy, have I learned my lesson. I had been thinking of rigging some kind of cat door for her, but now I wonder if I can't set up one of those doors that's rigged electronically to her collar, so only she can use it. Unfortunately I don't have any doors or windows that are really well set up for that...
Argh, must go off to work. Thanks for the empathy/anecdotes all!