This message comes from The Economist, introducing The Economist Insider, a new video offering with

twice weekly shows featuring in-depth analysis and expertise to make sense of an increasingly

complex and dangerous world. More at Economist.com slash insider.

Hey, shortwavers, Emily Kwong here. If you want to support our show, one thing you can do that is free, easy, and only takes a few minutes, is to leave us a rating or review. On whatever app or platform you're listening to, there's usually a place to sign in and leave some kind of message or five stars, if you would like. It really helps new listeners find our show, and we

really do read what people write. Like MF. Ruthie, who wrote last week, your pod has the most

relevant and creative material. You are a daily experience in Ruthie's life. Keep it up for us

nerds out there. Ruthie, thank you from one nerd to another. And thank you all for

listening for taking a sec to let us know what you think of our show and sharing it with those you love.

Okay, on to the episode. You're listening to Shortwave from NPR.

Hey, Shortwavers, it's Emily Kwong here, and it is that time of year again.

Can you feel the crispness in the air?

Can you hear the crunch of dry leaves, smell the haunting presence of pumpkin spice?

Oh, God, pumpkin spice.

That is NPR science correspondent, Nell Greenfield Boyce.

Hey, Nell.

Hey.

You don't want to talk about pumpkin spice today.

I mean, it's fine in moderation, you know, but like when I think about autumn, I think about real pumpkins and, you know, you said the leaves and whatever. But mainly, actually, I think about birds.

The birds, yes. This is their time to migrate, right? There's a lot going south for the

winter right now. Yeah, a lot. Like every night, hundreds of millions of them are taking to the air.

And like, we don't really notice because this is happening in the dark at night while we're

sleeping. But like huge numbers of birds are flying overhead. I hear them in the morning when they're on trees,

...