Frogs can scream but we just can’t hear them

Many people wonder whether frogs can scream especially when they arch (弓起) their backs and open their mouths. Recently, scientists recorded the first case of such a scream sound. In fact, the sound is a “defensive ultrasound (防衛式超聲波)” used by amphibians (兩棲動物). Scientists in Brazil (巴西) noticed that small leaf litter frogs (落葉蛙) arched their backs and opened their mouths wide. They looked like they were screaming but the scientists ...Read More