Do you know about the Congress Bridge bats in Austin? The world's largest urban bat colony summers under the bridge so they will be there for DAC next June (in winter they migrate to Mexico). Almost every evening an estimated 1.5 million Mexican free-tailed bats emerge at dusk over a period of about half an hour. Each night they eat around 10-15 tons of insects. That's a lot of mosquitos. Watch from the bridge, or, even better, get a cocktail from the lobby lounge of the Four Seasons hotel and watch from their balconies. There will be lots of good stuff to see at DAC but be sure to see this too. It's just a 10 minute walk from the convention center.