Moss piglets, water bears also known as tardigrades live everywhere from 5 miles below ocean seas to 6 miles high on mountain tops and everywhere in between.
In cryptobiotic form (an unwalking dead - or fake-dead state) tardigrades can be freeze dried and revived to their original condition, no harm done.
Tardigrades can survive boiling at 302°F, being frozen at-459.04°F, survive pressures up to 87,022.6 pounds per square inch. Water bears can live for more than 10 years without food or water. These teensy critters also can resist X-rayes with enough rads that would kill 1,000 humans.
Some moss pigglet fossils date from the Cambrian period 530 million years ago.
Questions About Tardigrades
How many of these tiny creatures exist on the planet. I guesstimate there are trillions of tardigrades and that just might be a low estimate.
How many water bears are consumed by humans every day? Ewwwww! Yes, tardigrades live on vegetables, lettuce, spinach, broccoli and so on and all the rinsing in the world won't shake those radiation-sucking space piglets off their perch. They are harmless, consider them extra protein.
So, since it's nearly impossible to kill tardigrades, when humans eat these tiny tardigrades do the little creatures die or just enjoy an internal vacation trip thruogh our digestive systems, visit a few relatives and meet new friends. That's a good question :-)