Want to hear “one of the rarest sounds on earth”?

Phil Torres of The Jungle Diaries YouTube channel recently took to the forests of Mexico, where millions of monarch butterflies migrate every year.

And, along with some truly stunning visuals (there are literally millions of the creatures hiding in the trees), he was able to capture an incredible sound: Millions and millions of butterfly wings all flapping at once.

The whole video is pretty incredible, but the actual “sound” portion starts around 3:35.