BCI and the Texas Department of Transportation recently completed a study of some 5,000 structures across the state, and the state agency is working bat-friendly design into new bridge construction as well as designing culverts that will provide additional bat habitat. Return to the beginning of this story. Each night around sunset, as they have for more than a decade, 1.5 million bats will leave the bridge's underbelly on food runs that blacken the burgundy sky and make for a unique brush with the natural world. In a city lousy with cheap thrills, the nightly emergence is the best, and it's no secret. In August, when the emergences are thickest, so are the crowds.
Bats are blood-suckers.
Three of the nearly 1,000 species of bats are vampires. They live only in Latin America, and feed primarily on the blood of cattle, horses and pigs. But their numbers are slipping as they continue to lose habitat, which is partly why they've adapted to bridges.