In a grove in the mountains of Mexico, a half a billion monarch butterflies sleep clinging to the trees. Having traveled from as far as Canada to escape the cold winter, they return to this exact spot. How they’re able to do that, no one knows for sure. This rare spectacle is caught on camera with the help of a spy “hummingbird.”
They huddle together while resting to conserve warmth and wait for the sun to heat up their wings. And then it’s time to fly. What starts off as a trickle soon becomes a swarm of beautiful butterflies covering the sky! It’s a breathtaking sight to behold.