Water Bears!

Thanks once again to Animal Planet's Most Extreme, my son has a new fascination - water bears! I don't recall ever hearing about water bears (tardigrades) before, but now that we have we're hooked. They are totally fascinating! Water bears are wee microscopic beasties that look like some weird combination of moles, frogs and bears. Although they are microscopic in size (measuring about 0.3-0.5 mm) they have legs (4 pair), a mouth (which they use for sucking the liquid from moss and lichen), a brain, and eyes. They have skin, muscles and nerves. Some even have tiny claws! Just watching them walk is mindboggling because they look so familiar yet so foreign. And they're actually quite cute! There are two sexes and they exhibit sexual behavior and lay eggs. But perhaps the most interesting thing about them is that they can "dehydrate" themselves (called a "tun" state). In that state they can withstand extreme conditions such as radioactivity, intense heat and cold, pressure, and acids. But it only takes a drop of water to revive them! We don't have a good microscope at the moment, so we have been scouring the Web for pictures and videos of these little critters. Our favorite by far is this one:

http://tinyurl.com/55yab

This site has some interesting clips and pics as well (including the one above):

http://www.baertierchen.de/wbwb.html

Once we move into our house, which has a wooded area with lots of mosses and lichen (a great place to find water bears), perhaps we can finally get a good microscope and go on a "bear hunt" of our own!