The bats are here, and they should begin increasing in number. The mother bats have probably just about given birth and their young ones will soon begin to make the nightly feeding trek. It's estimated there are around 1.5 Million bats under the Congress Avenue bridge when they're at their peak number. This is the largest bat colony in North America and truly a wonderful sight to see. It takes around 45 minutes for all the bats to fly out from under the bridge when they're at their peak. This is a truly unique event and one that every one of us UT students should enjoy at least once.