Scientists just found wild underground tunnels on two continents—and no, they weren’t made by humans or rivers. In Africa and the Middle East, there are microscopic tunnels in solid rock that hint at a totally unknown lifeform. Meanwhile, in South America, you can literally walk through massive caverns dug by giant prehistoric sloths and armadillos. Both discoveries are rewriting what we know about life shaping the planet from the inside out. Who (or what) made these tunnels? The mystery is still wide open! #Science #AncientMystery #ScienceNews