I was on this amazing hike in one of the most beautiful parts of Kauai, high up on the mountains on a knife-like ridge.

We were covered in mud, we were climbing, you know, using ropes. It's so steep and muddy and gorgeous and huge vistas.

Emma Maris is an environmental writer. Recently, she wrapped up a big story for National Geographic magazine. A story all about rats.

And when I caught up with her, she was just back from a bit of a working vacation on the Hawaiian Island of Kauai.

And we come around the corner and we see one of these traps and there's a sort of a penumbra of dead rats.

That's right. Even after months of reporting on rats, Emma just couldn't get away from them.

That's because they're an invasive species in Kauai. They're populations out of control and they're wreaking absolute havoc on local endangered sea birds.

The rats in this mini graveyard were killed by an extremely effective extermination solution.

It's something that seabird conservationists had been trying out.

The presence of the rat triggers a pressurized CO2 capsule that shoots a bolt into the head of the rat,

kind of like at a slaughterhouse, except on a much smaller scale.

What do we have to spend your time in paradise, right?

Once you get hooked on rats, you can't really stop.

Emma's Hawaiian rats, so far, I sound terrifying, but also strangely captivating.

I mean, rats occupy this weird place in our psyche.

Why do we gleefully compare horror stories about the big old rat we saw behind the dumpster?

And then we cheer when we see when carrying a whole slice of pizza down to fly to stairs on YouTube.

I'm Vaughn Wallace and you're listening to Overheard at National Geographic.

It's a show where we get to eavesdrop on the wild conversations,

naturally, the explorers and scientists are having every day.

And then we follow them to the edges of our big, weird, and beautiful world.

This week, we're unpacking our special relationship with humanity's little rodent frenemies.

...