The Hills Are Alive With the Sound of Ifrits

Especially sand dunes!  Where I grew up, the sands "barked."  You would kick along through dry layers of sand, and it sounded like barking dogs.  But with the right combination of the height of a sand dune, angle on the dune, and ambient temperature, sand dunes sing.

They usually sing one note, most commonly an E, F, or G.

In this report over at Atlas Obscura, the video at the bottom gives you more information on how some sand dunes move to their own inner song.  The other videos are specific locations around the world of singing sand dunes.

Trust me--once you hear a couple of these dunes sing, you completely understand how people decided that ifrits haunted the deserts.