There live all over the world little critters called tardigrades. There are several thousand species worldwide. They make their living sucking the juice out of lichens and moss, primarily, although recent discoveries seem to indicate that some tardigrades live off other tardigrades. They're not that small as microscopic organisms go, and easily seen under the common home microscope.

Here's why they're weird - they can be frozen, subjected to radiation levels that'd kill us many times over, dessicated, put in a vacuum, and subjected to pressure much higher than that found in the deepest ocean trenches, and survive. They lay dormant during dry and cold seasons, to return to active life when moisture and warmth return.

If any of y'all have a kid at home that needs a science project idea, this'd be a great one.

Google for tardigrades, and you'll get lots of good links, to include a site when they were used by a graduate student in a study to measure air pollution.