How long do vampire bats live?

According to National Geographic, the average life span for a vampire bat living in the wild is nine years. The Cincinnati Zoo points out that they live up to 20 years in captivity.

Vampire bats are relatively small. Adults are about 3 to 4 inches long and weigh just 1 1/2 ounces. The bats live in the rain forests, scrub lands and deserts of Mexico, Central America and South America. Vampire bats typically drink the blood of livestock and wild animals, but humans are not usually victims. To feed, a vampire bat makes a puncture with his teeth and licks, rather than sucks, the blood. The saliva of vampire bats contains chemicals that prevent the blood from clotting during feeding.