Pretty cool wee beasties; lots of photos and videos just a google away.
My daughter likes looking at these as well, though we haven't ever looked at real ones -- that's a project worth trying!
Currently we're growing butterflies (got 5 little caterpillars delivered by post in a jar with food for them -- they wandered around and got fat in there, then made chrysalises which we transferred to a big mesh cage (where we now have 1 chrysalis left and 4 butterflies; we're feeding them mashed ripe banana and flowers with sugar water dripped on them).
One of the caterpillars left his head out of the chrysalis... and we were startled to notice that the old head was left behind when the butterfly hatched out. They basically liquify in there and grow entirely new bodies from a new set of stem cells.
First, collect dry moss. Soak it in warm for 30 minutes. Squeeze out the moss, and examine the collected liquid closely under magnification, searching for localized motion. Even a 10x hand lens or loupe will be fine for identification, although a microscope would of course be better.