„Water bears“ is a colloquial name for tiny multicellular critters that have always delighted microscopists. They are properly called tardigrades („slow walkers“), and with four pairs of stumpy legs and lumbering gait, they do look a little like a microscopic bear (an eight legged, microscopic bear, that is). Tardigrades live in more places on Earth than humans do, so practically any handful of water has a chance of containing some. The easiest way to find them and care for them, however, is to look in scraps of wet moss.
https://www.wikihow.com/Find-and-Care-for-a-Pet-Tardigrade-(Water-Bear)?amp=1
Wikihow.com beschreibt hier wie man Bärtierchen züchtet