You’ve probably heard frogs croaking in the spring and summer as they find mates and their breeding territory. It’s usually after a rainy day and is their way of telling you that it’s the right time to mate and lay eggs in fresh water bodies.
Male frogs will croak individually or as part of a chorus to attract females. Their sound is unique, and their croak can tell you things like the species, virility, size and location of the frog. You can also hear them communicating with each other and a low groan will tell other males to stay away, while a quick release call is basically frog-speak for “let go”.
The noise is created by the vibration of the vocal cords. A frog’s larynx is designed to resonate and amplifies the sounds it makes, with a valve that controls the movement of air into and out of the lungs. This allows for a variety of sounds and pitches that make up a frog’s croak.
A frog’s vocal sac also looks a little bit like a bubble when it expands, which can be quite amusing. The frog’s ears are located directly on the sides of its head and act as a protective barrier. The frog’s ear drum is covered in a thick layer of skin that doesn’t have sweat glands (that would be very unhelpful when you’re swimming). This helps to keep the frog hydrated and protected from the noise of predators.