This is the longest shortest time from WNYC. I'm Hillary Frank. This is the fourth and final episode of our Sex and Parenthood series, which has been just so much fun to work on.

And it's been amazing to see so many of you engaging with each other on our blog and in our Facebook groups on this topic that is almost never talked about in a real way.

So please, please, please keep that up. Our website is longashortistime.com. Our Facebook groups are longashortist time mamas and longashortist time poppas.

So in this series, we've covered sex advice and childbirth injuries. In the last show, we heard a mom having the talk with her eight-year-old son.

Today's story is about teenagers. And what happens when they start thinking about having sex, which of course can lead to having babies.

Lots of schools try to prevent teen pregnancies with a dose of simulated parenthood. You know, they have the kids carry around eggs or sacks of flour. Pretend that they're babies that they have to take care of.

These days, some schools are replacing their eggs and flour sacks with robotic babies. They're made by a company called Reality Works.

One of the purposes of what we do is to help prevent teen pregnancy.

This is Tim Betcher, president of Reality Works. He told me the story of Rick and Mary Germain, the couple who invented the robot babies in 1993.

One night, they were sitting on the couch watching a television program on PBS. And in that program, kids were learning what it was like to care for an infant by carrying around eggs and sacks of flour.

And, you know, Rick, he looked over to Mary as wife and said, that's a dumbest way to learn what it's like to care for an infant.

Rick, as it turns out, is an actual rocket scientist, worked for NASA for a number of years.

A couple of weeks after seeing the show with the kids and the eggs, Rick got laid off. He had a lot of time on his hands.

Well, Rick went out to the garage, you know, tinkered around and created the very first baby. So, he took a dial that you could pick up at your Walmart store and put some electronics in that dial that cried.

You know, so that's how the first version worked.

Now, two decades later, the babies are more high tech. They have computers inside that make them cry all throughout the day and the night.

Their crying patterns are based on logs kept by actual parents.

Schools sometimes use the babies in a program called Baby Think It Over. Each baby costs over $600, including its car seat and clothes and bottles and other accessories.

In today's show, we bring you to a school where you'll get to hear those babies in action. The story is a collaboration with the wonderful This American Life. Stay with us.

The first time I saw a robotic baby was at my local pharmacy. It's one of those old, timey places with a candy counter and surgical supplies and a large selection of scented candles.

One day I was in the store and I heard this teenage girl behind me say, my God, this baby is so heavy. She had a car seat slung over her shoulder like a purse. For a second, I thought the plastic baby inside it was real.

The real ones are heavier, I told her. She groaned and whipped the car seat over to her other shoulder.

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