Mexican long-nosed bats have a taste for agave nectar, fueling their migration from Mexico to the U.S. each summer. Big Bend National Park in Texas and Hidalgo County in New Mexico are key destinations. Bat Conservation International announced on Tuesday that DNA evidence shows the bats are now traveling farther north than ever before. Researchers say drought in New Mexico's Bootheel region is pushing them to healthier agave sources. The bats, added to the endangered species list in 1988, are slow breeders. Restoration efforts are crucial to their survival and the genetic diversity of agaves.