Pooped!

Oftentimes the tallest object in an African village is a termite mound.  "Mound" is actually the polite way of saying "poop." Yes, termite who live under the ground excrete a substance that dries into somehing hard and concrete-like.
Year by year, the poop pushes higher into the sky, evidence of the zillions of unseen but active insects that live below.  We humans are very very much in the minority on this planet.