Monarch butterflies are unique — they’re the only butterfly to travel thousands of miles when the seasons change.

They travel from as far north as Canada all the way down to a few very specific mountaintops in central Mexico.

They don’t have a car, or an airplane ticket. They just have their two little wings. So we’re asking: How do they do it? How do they migrate thousands of miles? And why?

We’ll also look at why other insects don’t have to travel south for the winter — hint: it has to do with something in their blood. Of course, we have a mystery sound for you to decipher, too.

Brains On! is an award-winning audio show for kids and families from American Public Media.