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In Austin, Texas, an hour or so before sunset,

hundreds of people gather at this one bridge to wait for the moment when bats take flight.

Every time I go to Austin, I make a point to visit the Congress Avenue Bridge,

where these bats emerge to hunt all at once, clicking and squealing in a plume of wings.

Up to 1.5 million Mexican- freetailed bats take to the sky. This exodus can last 45 minutes, and it is hypnotizing.

I sort of fell into bats by chance, and really the reason I fell into them was because of

Austin, because of that enormous urban colony of bats.

Rachel Page is a behavioral ecologist and a staff scientist at the Smithsonian Tropical

Research Institute in Panama, but back in the day, she was a grad student falling in love

with bats for the first time because of this same

colony in Texas. I was mesmerized. How on earth are they not bumping into each other? How can

they recognize their own echolocation call? How are they also communicating socially with one another?

There are over 1,400 different species of bats found throughout the world. And the way

...