Bracken cave bat roost San Antonio Texas, USA
Bats have lived in this cave since the last ice age around 10 millennia ago. Today during the summer and enormous number of Mexican freetailed bats have their young in this cave. While most of them live in Texas a Mexico they roam as far south as central Chile and as far north as the southern states of the USA.
This cave contains the biggest concentration (known about) of mammals on earth with around 20 million Mexican freetailed bats arriving each spring. The colony eats an astounding 15,000 tons of insects each summer.
Watching the huge swirl of that exting the cave each evening is an incredible site.