I read an article recently about the world’s deepest subterranean vertical drop. The article goes on to mention:
At the foot of the Velebit cave are small ponds and streams, including one of the largest known colonies of subterranean leeches, Sutlovic Baksic said.
Subterranean leeches? I have to assume that at that depth in a cave there aren’t many larger living creatures that a leech might use as a food source. How do they survive down there?