You probably know that monarch butterflies make an epic journey each year, from the northern United States and Canada to Mexico, where they winter in the mountain forests outside of Mexico City.
But, we don’t know a lot about how they actually do it.
How does a tiny, paper-thin butterfly make it so far each year? Well, scientists have a new theory — and it has to do with the spots on their wings.
The Show spoke more about it with Jason Bittel, who wrote about it recently for National Geographic.
