Have you ever wondered what animal has a  

microscopic and nearly translucent invertebrate, 

can live almost anywhere, can survive almost 

anything, and is nicknamed the Water Bear and 

the Moss Piglet? It’s a Tardigrade! A Tardigrade 

is only 0.1 to 1.2 millimeters long. This extreme survivor can survive the toughest conditions.

             Did you just see alien? Oh, wait! That’s 

a Tardigrade. A Tardigrade has 8 short stumpy 

legs with claws. It only gets up to 1.2 

millimeters long, which means it is microscopic. 

It looks like a combination of a manatee and 

bear mix. It has a hose-like mouth. Its face 

looks like an alien’s face. It is also an 

invertebrate. 

            I hope that Tardigrade’s not hungry. A 

Tardigrade is an omnivore, which means it eats 

both plants and animals. It eats by sucking 

juices out of its food. A Water Bear eats about 

everything small. It has an exoskeleton which 

protects it from other creatures. Tardigrades 

and other microscopic life will eat a Tardigrade.

Tardigrades 

won't

care about this 

sign.

             I bet you won’t find a Water Bear in a pool of lava. A water bear lives almost 

anywhere. They can survive six times the 

deepest depths of Challenger Deep (the lowest 

point in the world). It can also live in space for 

10 days! A Water Bear was even found in an 

iceberg. It lives worldwide. It lives on land and 

in water. A Water Bear can survive -328°F, 

120°F, 27,000 PSI (pounds per square inch), 

harmful x-rays, harmful ultraviolet light, and 

the extreme vacuum of space!

       Look at some dust in a microscope. Do you 

see a Tardigrade? No, that’s the Tardigrade’s 

tun! A Water Bear will become a tun when it 

does not have enough food or water. The tun state helps it survive extreme conditions. A 

Tardigrade can be a tun for a few years. When 

Tardigrades go into the tun state, they roll up in 

a barrel shape called a tun. There are special 

types of tuns for different things. Sometimes, 

people mistake Tardigrade tuns for dust. When 

a Tardigrade is in a tun, it is like hibernation.