Tardigrades are microscopic eight-legged animals that have been to outer space and would likely survive the apocalypse. Bonus: They look like adorable miniature bears.
Around 1,300 species of tardigrades are found worldwide. Considered aquatic because they require a thin layer of water around their bodies to prevent dehydration, they’ve also been observed in all kinds of environments, from the deep sea to sand dunes. Freshwater mosses and lichens are their preferred habitat, hence their nickname, moss piglet.
Despite looking squishy, tardigrades are covered in a tough cuticle, similar to the exoskeletons of grasshoppers, praying mantises, and other insects to which they are related. Like those insects, tardigrades have to shed their cuticles in order to grow. They have four