Each spring, millions of Mexican free-tailed bats fly from under the Congress Avenue Bridge, but they weren't always welcome like they are today.

It’s officially time to see bats starting their nightly hunts in Austin Austin’s urban bat colony came home to roost under the Congress Avenue Bridge in late February.

When and why did the bats first come to Austin? Austin's Congress Avenue Bridge was originally built in 1910, but was revamped in the early 80's to include 3/4 inch to 1 and a half inch concrete ...

When and why did the bats first come to Austin? Austin's Congress Avenue Bridge was originally built in 1910, but was revamped in the early 80's to include 3/4 inch to 1 and a half inch concrete ...

You may be asking yourself if the Austin area bats are okay during freezing temperatures. When cold weather hits in late October to mid-November, the Mexican free-tailed bats migrate to Mexico ...

According to experts, Austin is home to the largest urban bat colony in North America. Approximately 1.5 million bats make the Ann Richards Congress Avenue Bridge their home for part of each year ...

Just check videos of the million-plus aggregation of Mexican Free-tailed Bats pouring from Austin, Texas’s Congress Avenue Bridge at sunset.

Austin's Congress Avenue Bridge is home to the largest urban bat colony in the world. A population of roughly 1.5 million Mexican free-tailed bats live under the bridge from spring until fall.

Bats living under the Walnut Creek Bridge in north Austin are being re-homed, according to the Texas Department of Transportation.

Thousands of bats flying from Austin's Congress Avenue bridge to the trees every day after sunset. Hundreds of cold-stunned bats have been rescued from around Austin this year.