Tardigrades have survived being exposed to the vacuum of space.
In 2007, dried tardigrades were flown into orbit and exposed to open space for ten days. Back on Earth, many of them revived and even reproduced.
Why is this true?
When conditions turn hostile, tardigrades enter a dried-out state called a tun, shutting down almost all metabolism. In that state they tolerate extreme cold, radiation and pressure that would kill most animals.
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More about animals
Animals are the easiest place to find facts that sound invented. Three hearts, blue blood, cube-shaped droppings, a punch fast enough to boil water for an instant — every one of these is ordinary biology to the animal doing it. The collection here leans on well-documented behaviour and anatomy rather than folklore, so each entry comes with a short explanation of why the trick actually works and a source you can read next.