Thousands of years ago, the United States was home to vampires. Fossils of multiple vampire bat species have been found in California, Texas, Florida, Arizona, and other states, dating from 5,000 to 30,000 years ago. Since then, winters in the southern United States have become cooler. But vampire bats still roam Mexico, Central America, and South America. And now, they are on the move. The common vampire bat (Desmodus rotundus) is pushing into new territory in both North and South America, and bringing new variants of rabies along for the ride.