Costa Rica  is home to 109 species of bats, which number fully half the mammal species in the country. You're sure to come across them during a visit. By day, certain species are easy to spot snoozing by clinging like vines to treetrunks. Another species gathers huge banana leaves together and weaves them into a kind of coccoon nest. Others, including Costa Rica's three species of vampire bats, inhabit nooks and crannies in the roofs of caves. All are communal.
My favorite species is the fishing bulldog bat, a mammoth-size critter with a wingspan 24 inches across and great gaff-like claws like eagles. It's so named for its feeding habits. Tortuga Lodge, in Tortuguero, is a great place to spot them swooping low over the lagoon to hook fish.
To learn about the ecology of these amazing creatures, head to Bat Jungle , in Monteverde. This two-year-old museum provides a fascinating insight into the lives of bats. Eight species flit, feed, and mate within a sealed enclosure–the bat flyway–behind a wall of glass. You can even don giant bat ears to gain a sense of their incredible auditory abilities.