You're listening to Shortwave from NPR.

Hey Short Waivers, Sydney Lupkin filling in the host chair today.

So around this time of year, about 5,000 feet above sea level in the mountains, you might see fresh snow.

In a place just like this, the enchantments in the Cascade Mountains of Washington State. About seven years ago,

neuroscientist John Tuthill went hiking.

He says it was beautiful but windy,

avalanche territory.

Like one of the most inhospitable places you could imagine and I just remember seeing an

insect on the snow and kind of being like wow that's crazy like how is it possible that this

insect is out here doing this.

John says these insects were moving uphill, basically running,

and even though they're tiny, they stood out against the rest of the mountain.

So you can kind of spot them at the rest of the mountain.

So you can kind of spot them at the corner of your eyes.

It's this like big open white expanse.

There's nothing on it at all except for this one little dot in the distance that's

kind of slowly moving.

These little dots in the snow are called snow flies

and they seemed unusual to John because these conditions are a death sentence

for lots of other insects.

Once it gets so cold that they can no longer move,

then they're screwed.

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