One monarch butterfly flies by. Then another, and another. As they fly, the butterflies seem to float1 in the sky. They make beautiful shadows on the ground below. They seem to be everywhere. In fact, there are so many butterflies that the groups look like beehives in the trees. And when they fly, the sound of 150 million monarchs wings creates a soft sound, as though it is raining. People say Mexico is the only place in the world where you can hear the sound of butterflies wings moving.
Every year millions and millions of monarch butterflies migrate from the USA. and Canada. They go to a place high in the mountains of Mexico. There, they can escape from North America's cold winter temperatures. To get there, the monarchs often travel over 80 kilometers a day. But what's really amazing is that the butterflies make the trip only once. Somehow they know exactly where to go.
After the butterflies arrive in Mexico, people gather to watch. The effect on people is amazing. Young and old, men and women, locals and people from far away-everyone is smiling and friendly. It's as though the butterflies encourage people to be their best.