From an evolutionary point of view, frogs were the first animals to really sing with tapes. Like people, frog's vocal cords are in the throat cavity. When the air passes quickly, the vocal cords vibrate to make a sound. In addition to the vocal cords, the male frog has a pair of external vocal sacs on both sides of his throat, which protrude outward to form two large airbags when he calls, making his voice louder. All kinds of shoes have different sounds and tones, and experienced people can tell which kind of frog is barking by the tones it emits. Both female and male frogs croak, but the croak of the male frog is louder than that of the female frog due to the acoustic sac.
Under what circumstances can frogs be happiest? When it is attacked by the enemy, it will make a quick cry. If we press the back of its body or pinch its side with our fingers, it will bark, and it will bark once. Several frogs crowded together. If one frog touches the other's back or abdomen, it will bark, too. If the environmental conditions are particularly suitable, it should also be called. For example, on a summer night, on the eve of rising temperature or about to rain, or after the rain, the frogs in the field came and went, as if in chorus.
In addition, frogs are also very excited during the breeding season, which is to attract heterosexual couples to mate.