Western Pipistrelle Bat The western pipistrelle has a higher pitched chirping call. This is the smallest bat in North America, with a wingspan of only 8 inches. Bats can change the design of their calls to fit the task -- navigating, searching for flying insects or gleaning insects off plants. Listen to the echolocation clicks of a Western Pipistrelle Bat. Return to Bat Echolocation Station © 1999 Oakland Museum of California |  Credits