So you think you’re pretty tough, don’t you? You think you live on the razor’s edge of life? Well, compared to many creatures on this planet, humans are soft. We like sunlight and water, and we can’t get too cold or too hot or else we’ll die. But extremophiles can live in downright hostile environments.

These unique organisms give us a better understanding of what kinds of life might exist way out in the cosmos. How cool is that?

Check out these five incredible extremophiles:

This creature is basically what it sounds like: a snotty stalactite. But snottites are actually colonies of cave-dwelling extremophile bacteria that live off volcanic sulfur — which, when combined with water, produces sulfuric acid. The waste products of the bacteria have similar properties to battery acid. If they weren’t so cool, they’d be incredibly nasty. Snottites truly look like a bunch of snot clinging to rocks.

Giant tube worms are beautiful creatures. They live deep in the Pacific Ocean — very deep. In fact, giant tube worms can be found up to several miles below the surface of the water.

These worms are typically found around “black smokers,” or hydrothermal vents in the ocean floor that emit particles with high levels of sulfur-bearing minerals. That means they can survive both extraordinary pressures and high levels of hydrogen sulfide

We’d better be thankful that water bears — aka tardigrades — tend to be less than half a millimeter long, because they would otherwise dominate the galaxy. These microorganisms are basically the toughest creatures on the planet.

Water bears are known as polyextremophiles, which means they can survive in a variety of environments that we would consider completely unlivable. How, you may ask, can a mere water bear compete with your big guns? How about the ability to live without water or food for 120 years? Or the ability to withstand pressures six times greater than what is found in the oceans?

Not convinced? Well, they can also survive temperatures just above absolute zero and above boiling point, as well as higher radiation than what humans can handle — like, hundreds of times higher. Water bears can even survive in possibly the most hostile environment of all: the vacuum of space. Don’t mess with water bears!

Like the water bear, loricifera are teeny tiny microscopic animals that live in marine sediment. There are 22 species in the loricifera phylum, but three of these species particularly stand out.

In the Mediterranean Sea, about 3,000 meters down, live these strange organisms. What makes them so unique? They live their entire lives without oxygen or sunlight. These little critters live in almost completely salt-saturated brine — possible only because they don’t rely on mitochondria for energy. Instead they use something called hydrogenosomes.

Let’s just call these wingless insects “icebugs,” because that scientific name looks like the name of alien villain on Doctor Who.  Usually, when we think of insects, we think of a warm climate. But Grylloblattidae live in basically the opposite environment: extremely cold locations — between about 34 and 39 degrees Fahrenheit — and usually at higher elevations. They aren’t quite as hardcore as our water bear friends, however. It’s possible to kill an icebug if the temperature gets too low.

Photo Credit: Eye of Science/Science Source Images