Bats are also a much younger group than birds with the earliest bat fossils coming from the Jurassic Period, a mere 65 millions years ago. Bats live in caves, but also in trees, under bridges, and maybe in your house.
Vampire bats do exist elsewhere.
Some cultures revere bats as bearers of good fortune or messengers from the spirit world. Bats are the only indigenous mammal remaining on Puerto Rico. Bats feed on flowers, fruit, insects, birds and fish, and are vitally important in pollination and insect control. Bats are not blind, but with the use of echolocation and the fact that so many of them feed at night when there is little light, their eyes are of less importance than their hearing. Both bats and bears in northern climates hibernate during cold weather, but since it doesn't get cold in Puerto Rico, bats here don't hibernate.