It generally needs to be moist to function effectively. The amphibian's skin is also generally highly permeable. It allows water to be absorbed and lost, and sometimes is involved in gas exchange supplementing respiration through the lungs. The skin of all amphibians contains numerous poison glands, which are used to discourage predators. Amphibians generally have simple pedicellate teeth which are used to grasp their prey, but many have greatly reduced or no teeth.
Most amphibians have very muscular and flexible tongues.
Their tongues are also highly extrusible and often sticky with mucus to adhere to prey. In most amphibians three senses are critical to survival. In frogs the male often attracts the female by calling to them. It is therefore critical that a frog be able to distinguish the call of their species and to separate it from the background noise. Acute vision and often color recognition is also important in many amphibians.