Amongst all of the bugs you might find underground, there are six endangered karst invertebrates in Austin area caves. Some of them are so small that you really could sneeze and never see them.
The Tooth Cave Spider is only 1.6mm and is the smallest of these invertebrates. The Tooth Cave Ground Beetle is one of the larger at up to 8mm.
What is crazy about this is that these invertebrates eat bugs and organisms that are even smaller than them! Low pollution levels and open space above the cave allow for healthy populations of these invertebrates. Healthy invertebrates and caves mean that our aquifers are healthy, too.