Scott Detrow

Listen to Trump's Terms from NPR.

Listen to Trump's Terms from NPR.

Kids are going to be kids wherever they are.

Kids are going to be kids wherever they are.

Kids are going to be kids wherever they are.

This is Eder Peralta, NPR's Mexico City correspondent. It was December, and he was in a train yard in northwest Mexico.

This is Eder Peralta, NPR's Mexico City correspondent. It was December, and he was in a train yard in northwest Mexico.

This is Eder Peralta, NPR's Mexico City correspondent. It was December, and he was in a train yard in northwest Mexico.

I did this when I was a kid.

I did this when I was a kid.

I did this when I was a kid.

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.

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.

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.

The trains moved so fast that jumping on directly would be impossible for most of the migrants.

The trains moved so fast that jumping on directly would be impossible for most of the migrants.

The trains moved so fast that jumping on directly would be impossible for most of the migrants.

The migrants Eder and his photographer were following finally found the train they wanted, and they got it to stop. They climbed up to the top of the train, and Eder and his colleague joined them. They all spent a frigid night riding north at 50 miles an hour. In Mexico, this train is called the Bestia, the Beast. It's a treacherous and often deadly leg of the journey to the U.S. border.

The migrants Eder and his photographer were following finally found the train they wanted, and they got it to stop. They climbed up to the top of the train, and Eder and his colleague joined them. They all spent a frigid night riding north at 50 miles an hour. In Mexico, this train is called the Bestia, the Beast. It's a treacherous and often deadly leg of the journey to the U.S. border.

The migrants Eder and his photographer were following finally found the train they wanted, and they got it to stop. They climbed up to the top of the train, and Eder and his colleague joined them. They all spent a frigid night riding north at 50 miles an hour. In Mexico, this train is called the Bestia, the Beast. It's a treacherous and often deadly leg of the journey to the U.S. border.