Bats are mammals.
Bats are mammals of the order Chiroptera ( [ kaɪˈrɒptərə ] from the χείρ - cheir , `` hand '' and πτερόν - pteron , `` wing '' ) whose forelimbs form webbed wings , making them the only mammals naturally capable of true and sustained flight . Bats are the second largest order of mammals ( after the rodents ) , representing about 20 % of all classified mammal species worldwide , with about 1,240 bat species divided into two suborders : the less specialized and largely fruit-eating megabats , or flying foxes , and the highly specialized and echolocating microbats .