In Austin we went to the Ann W. Richards Congress Avenue Bat Bridge (Bat Bridge for short), where hundreds of people gathered every evening to watch 1.5 million bats exit from underneath the bridge to feed on their fav food - mosquitoes (and other flying insects).

Hundreds of tourists gather on and below the bridge to watch the bats fly at dusk.

Hundreds of tourists gather on and below the bridge to watch the bats fly at dusk.

The Mexican free-tailed bats were much smaller and harder to see than we had expected.

The Mexican free-tailed bats were much smaller and harder to see than we had expected.

Guided boat tours on the river lit up the bridge with a red light.

Guided boat tours on the river lit up the bridge with a red light.

Supposedly, the red lights help make the bats more visible in the darkening evening.

Supposedly, the red lights help make the bats more visible in the darkening evening.

A 1980 renovation created an inviting maternity roost for the migrating bats.

A 1980 renovation created an inviting maternity roost for the migrating bats.