Frogs are part of a diverse group of amphibians. The total number of recorded species of frogs is approximately 4,800. Adult frogs typically have protruding eyes, a stout body without a tail, limbs that fold underneath them and a cleft tongue. When common frogs are picked up or otherwise disturbed by humans, predators or household pets, such as dogs or cats, they may let out a shrill shriek. This is one of their ways of naturally defending themselves by frightening predators. Various species of frogs may also use poison glands, camouflage, bluffing or deception to avoid predators or scare them away. In this video, a frog lets out a piercing scream in order to try to scare the human away.