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When you think about Hawaiian fauna, you might picture the colorful fish you see while snorkeling or all those pretty native birds. You probably do not think of a half-centimeter long, brown bug with long legs that lives inside of frozen volcanoes.

But maybe you should, because the WÄ“kiu bug or Nysius wekiuicola is arguably awesomer than any other animal that calls these islands home. You see, it's only found at high elevations, at least three kilometers up the side of Hawaii's largest volcano, Mauna Kea. There, it lives inside mini volcanoes called cinder cones that dot the sides and summit.

And despite it being Hawaiʻi, life there is no tropical vacation. Temperatures flip flop daily between -15 and positive 47 degrees Celsius. And even though the Hawaiian islands are tropical, snowfall on the top of the volcano is common.

So pretty much nothing grows there apart from a bit of moss on the rocks. Which means you wouldn't expect to find any animals. But there are a handful, including the wēkiu bug.

And it has some unique ways of dealing with this inhospitable habitat and the apparent lack of food. To cope with the environment, wēkiu bugs mostly hang out in between loose rocks where they can scramble down deeper into the crevices at night to avoid strong winds. Even then, the cold can penetrate so deeply that the bug's cozy holes freeze, too, so it has another trick up its sleeve.

It's able to supercool its body, which means its body can reach really cold temperatures, like -18 degrees Celsius, without its internal fluids freezing. But how it does this is still unknown, as it doesn't use the same proteins most supercooling insects do. And this leaves the issue of food, of course.

Like, bugs gotta eat! The wēkiu bug's relatives are seed-eaters, so you might think it eats the moss or plant material somehow. But it doesn't.

It's a scavenger-predator that prefers its meals delivered. It gets its protein and fluids by feasting on the insects that get carried up the volcano by strong winds. That makes it a part of an aeolian ecosystem, because the bugs' main source of food is brought in from outside the area they're living in.

To get at those juicy insides, wēkiu bugs use their specialized stabbing and sucking mouthparts, which their Nysius cousins use for sucking out the centers of seeds. And because those bugs evolved from seed-eaters, and so are no good at catching live prey, those frigid night temperatures might actually help them subdue their meals, if they aren't dead or frozen already. Those winds are cold.

According to entomologist Jesse Eiben, mitochondrial DNA evidence suggests that wēkiu bugs split off from their seed-eating relatives right around 800,000 years ago, which is relatively recent, evolutionarily speaking. How they got up on the volcano in the first place is still a bit of a mystery, but Eiben and his colleagues think that it's possible a winged ancestor flew over from a neighboring island. Then, over time, the bugs lost their wings because they had a fairly stable food source and very little competition so they didn't really need to go anywhere.

And that all makes sense, except now, the volcanoes are changing. Biologists are concerned that wēkiu bugs may struggle as their habitat shrinks because of climate change or as observatories are built on the summit where they live. So they're continuing to study the insects to figure out how to best conserve them.

And hopefully, we aren't seeing the last of this peculiar, hardy, insect-slurping bug. If you love to learn about weird, amazing things like this, you'll probably will love our podcast. It's called SciShow Tangents.

It's is a collaboration between Complexly and WNYC studios, hosted by me, and a bunch of the awesome people who make SciShow happen. Every episode, we basically just get together and try to blow each other's minds with amazing science facts. We even have a segment where two of us go head-to-head to see who finds the most awesome fact.

And we play Truth or Fail, where we try to stump each other with two made-up facts and one real one. There's also poetry. Who doesn't want that?

And every episode ends with a fact about butts! So yes. If you like amazing facts and you like SciShow and you like the cool people who do this and want to hear us having a lot of fun together, you can listen to SciShow Tangents using the podcast platform of your choice. [ ♪ Outro ].