How Does a Cricket Chirp?

Wing Against Wing

Not all crickets chirp. Only the male cricket chirps, and he does not do it by rubbing his legs together, which is a myth perpetuated by popular movies featuring crickets. Male crickets have a large vein running along the bottom of each wing. The vein has "teeth," much like a comb does. The chirping sound is created by running the top of one wing along the teeth at the bottom of the other wing. As he does this, the cricket also holds the wings up and open, so that the wing membranes can act as acoustical sails.

The chirps are highly pitched, a bit higher than the highest note on a piano. You can tell the temperature by how fast a cricket chirps: The faster the chirps, the warmer the night is. Dolbear's Law states that one can determine the temperature by counting the number of chirps a cricket makes in 15 seconds and adding 40 to that number. In particular, the snowy tree species of cricket, which is common in the United States, is an example of this.

Different Chirps Mean Different Things

Male crickets chirp most often at night, and usually do so to attract females, although there are other reasons male crickets chirp, or sing. The first and loudest cricket song is that used to call female crickets. This chirp also repels males. Once the female cricket draws near, the male will switch to a softer, quieter chirp. This is done by moving the wing in a different, gentler manner over the teeth of the other wing.

Male crickets also have a threatening chirp. They make this loud, aggressive sound when they sense another male cricket is nearby. The wings move in an angry, slashing motion to make the aggressive chirp. Finally, male crickets will make a brief copulatory song after he has successfully courted a female.

Both male and female crickets can hear the male cricket's songs, and they do so by use of an "ear" that is located on their knees. This ear even has eardrums similar to that of humans.

Highly Prized Songs

Crickets have a long history of being kept as pets because of their chirping. In ancient China and Japan, they were considered good luck. The wealthy in those countries during ancient times frequently kept crickets in gilded golden cages in their bedchambers, because crickets usually only sing at night. Even the less wealthy would keep crickets in their homes, albeit in bamboo or wooden cages. Today, some still keep crickets as pets and enjoy their unique chirping.

Resources

• More about crickets from the University of Arizona