At dusk, April through October, millions of these mammals fly out from under the Congress Ave. Bridge to feed
... and that on the nightly flights out from under the bridge, the Austin 
bats eat ... the population under the Congress Avenue Bridge grew to be the 
largest... [DOC] [TLE] Austin Congress Avenue Bridge Bats - Urban Bat Colony Stock ... [PAR] The colony is estimated at 1.5 million Mexican free-tail bats.