So in January 2004, one afternoon I found a little deermouse camping in my office trash can. The mouse stared up at me with big dark eyes, and being the cold-hearted creature that I am, I of course decided that rather than turn the thing out in the cold, I'd smuggle the mouse home and make it a cherished pet.
The trip home was uneventful, and I decided to convert a small plastic organizing bin into a mouse habitat. My wife and I lined the bin with newspaper, provided clean tissues for bedding, and tried to figure out what a mouse would like to eat. We decided to put cling wrap around the sides of the bin instead of covering the top completely. Our big mistake was failing to realize mice can jump several feet.
The next morning, the mouse was gone. We searched, but there was no sign of the thing, which was of course quite worrisome--we'd just unintentionally infested our house. That evening, we heard a bit of scrabbling, and I saw a dark shape zip by in the corner of the kitchen. I tried several different variations of bait and traps, which elicited no response from the mouse. Listening closely, we decided there were faint gnawing sounds coming from within a gap between the kitchen cabinets and the wall.
Horrified, but unable to figure out how to capture or kill the thing (from friend to mortal enemy in one day!), I set one final trap and went to bed. This trap is very simple--it's just a waste bin with bait at the bottom and a ramp leading up to the top. The idea is the mouse climbs up the ramp (A) to get the bait (B), but is then unable to climb out of the sheer walls (C). The next morning, we found the bait was eaten, but the mouse had (of course) leapt out.
That evening, I added a chunk of cardboard as a deflector (D) to the top of the trap, turned out the lights, and tried to be very quiet. After several hours, I heard the sound of a high-velocity mouse head bonking against the cardboard deflector, turned on the lights, and jammed a bag over the top of the trap. After a very careful transfer process, the mouse was back safely inside an upgraded bin, now without a gaping hole in the top.
Flushed with success, we started reading about our now hard-earned pet. To our horror, we discover that Deer Mice are a leading carrier of the Hanta virus, which has a 40-50% fatality rate. Worse, an Illinois man and several people in Indiana had died (horribly) of the Hanta virus within the past several years; in each case after coming in contact with concentrated dried droppings from wild Deer mice.
And so, having contemplated setting a lethal trap to kill the mouse, we discovered that the mouse may in fact be lethal to us. The sensible thing to do at this point would have been to just kill the mouse using some quick, painless method. As softies, we decided to let the mouse go free in a nearby wooded spot, despite the cold and the snow on the ground.
To assuage my substantial guilt, I carefully prepared a cardboard tube filled with fat-rich birdseed. We picked a nice spot beneath a large rock, I packed the tube into the ground, and (trying not to breathe or touch the biohazard mouse) I lifted the mouse's whole little nest out of the bin and deposited it onto a cleft in the rock. To my enduring shame, I found not only one mouse, but at least two hairless, helpless baby mice in the nest: the mouse I picked up at the office had actually been pregnant the whole time.
On the bright side, having let this tiny family "free" in the dead of winter, my wife and I did not catch the Hanta virus; nor do we now own an exponentially growing supply of increasingly inbred Deermice. However, the guilt is still strong with this one; so my wife bought me a pair of (male) commercial mice. They're not as cute, but they are more playful, and they're not infected with any deadly diseases...