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...
