Cathal Garvey issued a challenge on the Thingiverse list a few hours ago, "Mouse get!" The challenge is to build a humane mouse trap that can be printed on a Makerbot, and that will trap a mouse and keep him in!
Uploaded here is my attempt at designing such a trap. I'm printing it now, and will test it once it's fully printed (in a few hours.) It's not the most material efficient design, but I think it should foot the bill for a maximum security mouse trapping and storage facility. In fact, if you print it out of PLA, I'm willing to bet that this trap would stand up to a mouse wielding heavy artillery (heavy for a mouse, that is.)
The idea is that when the mouse steps on the ramp, the support will be pulled away and the trap will close quite tightly. I tried to build it myself, but the bottom piece failed part of the way through because of some issues I'm having with my bot.