Kids are going to be kids wherever they are.

I remember there was this one kid who was putting plastic bottles on the train tracks just to see what happened to them.

This is Adair Peralta, NPR's Mexico City correspondent.

It was December, and he was in a train yard in northwest Mexico.

So at some point I gave him a little coin, so he could put it on the train track and see what happened to it.

And indeed, I had never done this before.

I did this when I was kid.

Yeah, and it flattens it, right?

It's like one of those machines.

This was a moment of downtime between many periods of acute motion.

Hundreds of migrants were waiting for freight trains, hoping to jump aboard and ride north

toward the U.S. border.

They have, like, their whole lives with them.

You know, they have just bags full of coats and blankets, and they have jugs of water.

When a train would finally approach.

They're so heavy that, like, the earth beneath it sort of heaves

as they move across, right?

It almost feels like the gravity of the train pulls you toward it.

The trains move so fast that jumping on directly

would be impossible for most of the migrants.

So they have this term that they say,

we're going to puncher the train,

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