Nine species of bat live in Vermont, and five of them are so uncommon that Vermont has listed them as threatened or endangered species. The Vermont populations of these bats have decreased because of white-nose syndrome, a disease that started killing bats around 2006. All the listed bat species spend the winter clustered in caves or mines where white-nose syndrome can infect new bats.
Two of the state-listed bat species are also rare nationwide and are listed as federally threatened or endangered species. The northern long-eared bat was first listed as federally threatened in 2015 because its populations had declined due to white-nose syndrome. The Indiana bat was listed as a federally endangered species in 1967 long before white-nose syndrome was identified.