Leigh Harlen is a writer of science fiction, fantasy, horror, and blends of all three. Perhaps you’re here to read some of it. Or maybe you just want to learn more about bats because they were shouting enthusiastically on Twitter. If so, the largest bat colony in the world is Bracken Cave in Texas. 20 million Mexican Free-tailed bats roost there about eight months out of the year. Think about that. 20 million. Cool right? That’s a lot of guano. Be nice to bats. They’re awesome.