Hungry bats whipping through the blackness to gulp down insects may have driven moths into daylight—creating what we know as butterflies—suggest Canadian researchers.
The idea springs from their discovery of butterflies that have ultrasonic ears, explains Jayne E. Yack of Carleton University in Ottawa. Night-flying, tropical butterflies of the superfamily Hedyloidea have on their wings ears sensitive to high frequencies, Yack and James H.