Megabat evolved early in the lineage of chiropterans. Although echolocation was later lost in family Pteropodidae, bats in the genus "Rousettus" are capable of primitive echolocation through clicking their tongues, and some species have been shown to create clicks similar to those of echolocating bats using their wings. Both echolocation and flight are energetically expensive processes. The nature of the flight and echolocation mechanism of bats allows for creation of echolocation pulses with minimal energy use. Energetic coupling of these two processes is thought to have allowed for both energetically expensive processes to evolve in bats. The loss of echolocation may
Echolocation jamming produce ultrasonic clicks in response to the echolocation calls bats use while attacking prey. For most species of tiger moth these clicks warn bats that the moths have toxic compounds that make them distasteful. However, the tiger moth "Bertholdia trigona" produces clicks at a very high rate (up to 4,500 per second) to jam bat echolocation. Jamming is the most effective defense against bats ever documented, with jamming causing a ten-fold decrease in bat capture success in the field. The possibility that moths jam bat echolocation arose with an experiment report published in 1965 by Dorothy Dunning and Kenneth Roeder.