Pop!

Like organic popguns, mesquites fling their seeds from pods exploding in the dry heat.  Not long after I moved here, 15+(!) years ago, I was sitting in a friend's backyard, when I realized there were these odd snapping noises all around us.  She--a Phoenix native--hadn't even noticed and was at a loss to explain.  But I just happened to catch some movement out of the corner of my eye--a popping pod and seeds disturbing the litter of spent seed pods under the tree beside us!  Mystery solved!