> what do people do to keep their small kids from =
> falling out of the top bunk at night?

My kids are 38 and 40, but their kids, my grandsons,
I care about.  So I made a safety net out of some
Westy gray vinyl cloth that I had around.  It also
keeps their pillows from falling.  Indeed, even adult
pillows....

http://jones.colorado.edu/VW/SafetyNet

It is attached under the upper bunk cover screws and
it just flips back on top of the cushion before it is
folded over, so it ends up between the cushions when the
bed is closed.

Richard