If you think mice are cute and can't imagine killing one, please don't read this. Liz, try this tonight and see if it doesn't work: Take a small piece of toothpick or other small piece of wood or something which will absorb fluid. Fix the piece of wood in the bait receptacle of a breakback trap. Very carefully touch a bit of vanilla extract to the wood, letting the wood absorb it. Then set the trap as usual. Why the wood? Because as Jane pointed out, mice (and rats, too) can be extremely facile in getting bait out of traps without setting the trap off. The vanilla impregnated wood will cause them to chew and tug on the wood - and set off the trap. One caveat: if you have rats rather than mice, and if they set off the mouse trap baited with vanilla, they probably will not go anywhere near a rat trap baited with vanilla. You'll have to use another bait (I have an excellent one in mind). Jim McKenney Montgomery County, Maryland, USA, USDA zone 7, where it's already down into the 20s F and the low is predicted to be 10 degrees F - and it's only December!