Veering off completely... Has anyone else tried the Victor "Quick-Kill" mouse traps? 
These are very interesting as they induce the mouse to try to crawl into the little "hole" leading to the bait, pushing the cover UP, and tripping the trap. There seem to be many advantages to these: Very easy to set, very easy to bait (can even use grain!), almost no accidental "trips", etc...
I do think small mice might no be killed quickly if they approach from the side. :-(