The 6th mouse I trapped in about 3 days. I think this wipes out the family. BTW, you can mummify a little critter like this (or say a dead hummingbird, if you find one) by placing it on a pie plate in the freezer, wrapped in Saran wrap with air holes punched in it, and leave it for about two months. I learned this at a workshop on bones at The Bone Room, a great natural history store in Berkeley, Calif.
Note: they have invented a better mouse trap. The Ortho 0321110 Home Defense Max Press ‘N Set Mouse Trap has a “bait well” that you fill with peanut butter, so the trap is sprung by mouse digging around in it; this solves the problem of mouse deftly removing bait without springing trap. Ortho also makes a rat trap with the same feature.