For the past three decades, Austin, Texas has been home to nearly 1.5 million bats - and not just any bats, but Mexican free-tailed bats that have made their permanent residence under Congress Street bridge in the heart of downtown Austin. This is an incredible number of bats, so it's no surprise that during the summer months countless tourists come from all over the world to watch them exit their roost at dusk each night in search of food.