Half a million cave bats

This video from the USA says about itself:

More than 500,000 Brazilian free-tailed bats, emerging to forage at night, light up the pitch black darkness of New Mexico’s Carlsbad Cavern in this thermal infrared video.

The Wrinkle-faced Bat, Centurio senex, is listed as ‘Least Concern’ on the IUCN Red List of Threatened Species. This striking-looking bat inhabits moist and dry tropical forests of Latin America, from Mexico to Colombia and Venezuela. It is considered to be an uncommon species throughout its range, although occasionally it can be locally abundant under certain conditions: here.