Little Brown Bats are common in Mammoth Cave. Because of White Nose Syndrome, a disease caused by a type of fungus, 95% of Mammoth Cave's bat population has been killed by this disease.
This little bat was hiding, along the Historic tour trail. Eastern Red Bats get their name from their reddish coloration. Now, I am no expert on identifying bats, but I do believe this is an Eastern Red Bat.