Frogs use a myriad ways to defend themselves against predators. Some are poisonous. Some are brightly coloured. Some even inflate their bodies with air to appear bigger.
Another way frogs have been known to defend themselves, or alert others nearby, about a predator is to make loud sounds.
Recently, scientists have found that one tiny species of frog endemic to the Brazilian Atlantic rainforest emits ultrasonic sounds that are inaudible to humans but can scare off predators.
