"The Dark Knight" is Batman movie No 6. Since the beginning of the franchise, there have been two separate Jokers and, with Christian Bale, four different Batmen.
That might seem like a lot. But in Austin, Texas, where everything is bigger, they count their bats by the hundreds of thousands.
Austin is home to the world's largest urban bat colony. As many as 1.5 million Mexican freetail bats live right in the middle of downtown, squeezed underneath the Ann W. Richards Congress Avenue Bridge.
"Nothing like the smell of bat guano [excrement] in the evening," said Kelly Page, captain of the Lonestar riverboat that cruises around Town Lake to find the best vantage point to see this nightly event under the bridge.
"By the decibels of their chirping, I think they're going to come out relatively soon tonight," Page said one recent evening. "They're getting geared up."
Every summer night at dusk, tourists and locals wait as the bats, the only mammal that flies, start trickling out. For nearly an hour, they swarm out in a precise hierarchy that only the bats themselves understand.
Their population exploded after a bridge renovation in 1980, when designers added expansion joints and unknowingly created a bat paradise. The narrow openings provide a hospitable place for the bats to hang.
"Now, what they did not bet on at all is they had just created the most perfect bat habitat," Page said. "Couple that with great temperatures for bats to come down here."
Bats Aid Austin Tourism Boon
At first, the good people of Austin were not so sure about their new neighbors. That whole vampire thing makes people nervous. But these tiny creatures are not vampires. It turns out they eat 10,000 to 30,000 pounds of insects, including mosquitoes, each night. And if that's not enough, their nightly show pumps an estimated $10 million into the local economy. Not bad neighbors to have after all.
And, now, the bats are more than tolerated. They are revered. There is a bat statue downtown, an annual bat festival and a hockey team named the Ice Bats. And, of course, there are the nightly bat cruises that are more often than not completely sold out.
Page described the bat behavior from the helm of her pontoon riverboat. "They fly out every night," she said. "They go eat their food until they're full, which, actually, by the way, takes one-third of their body weight to consume in insects to make them full. Once they get that, they come back under the bridge to nurse their own young."
It has become an urban eco-tourism hit for the young and the old.
"We're looking at something you can't see anywhere else," tourist Bill Wilson said. "That's a good reason to come."
His wife, Barbara, added, "I think it's very spectacular. It just blew my mind. I didn't realize there were going to be so many."
All of these bats make Austin unique, and they fit nicely into the city's slogan.
"Our motto is, 'Keep Austin weird'," Page said. "Bats are completely 100 percent geared in that. How weird is it to have 1½ million bats right under your bridge, right in downtown? You know, that's pretty weird."