Ever notice when you are very still, you start to hear the sounds of nature emerge? When you are quiet is when you notice birds singing, tree leaves rustling and crickets chirping.
Whether you are quiet or not, usually, the birds and leaves will continue to make sounds. Meanwhile, crickets will only chirp when there is stillness.
Crickets are sensitive to floor vibration and noises. It is part of a cricket’s defensive mechanism to quiet down as soon as it can detect unwanted, possibly predatory creatures nearby.
Since most predators are active during daylight hours, crickets chirp at night.
First, Why Do Crickets Chirp?
Only male crickets chirp using stridulation, which involves rubbing the edges of their front wings together, in effort to discover female mates. They use their courting sound mostly during the daytime in safe places when a female is near in hopes she is inspired to mate with them. Chirping at night is typically used to fend off potential threats. An aggressive song helps males set their territory and claim access to females, while a triumphant song is done after mating to strengthen the bond and encourage the female to lay eggs instead of pursuing another male.
Hearing Without Ears
Crickets do not have ears like we do. Instead, they have a pair of tympanal organs on their legs, which vibrate in response to vibrating air molecules (sound to humans), in the surrounding air. A special receptor called the chordatal organ translates the vibration from the tympanal organ into a nerve impulse, which reaches the cricket’s brain.
A cricket is always on the alert for predators. Its body color is usually brown or black blending in with most environments well. But, when it feels vibrations, it responds to the nerve impulse by doing what it can to hide best—it goes silent. Crickets are extremely sensitive to vibration. No matter how soft or quiet you try to be, a cricket will get a warning nerve impulse.
Feel the Noise
Noise to a human is nothing more than vibrations traveling through the air and reaching our ears.
Think about the thumping of a loud, deep bass drum or the bass on your music system turned up. Humans can feel the music at that point. From this example, it is easy to see how noise and vibration are intertwined. Usually, in everyday life, humans will hear something first, but crickets will always feel it.
Male crickets are the communicators of the species. The females wait for the songs of the males to spur on the mating ritual. Female crickets do not chirp. Males make a chirping sound by rubbing the edges of their forewings together to call for female mates. This rubbing together is called stridulation.
Several types of cricket songs are in the repertoire of some species. The calling song attracts females and repels other males, and is fairly loud. The courting song is used when a female cricket is near and encourages her to mate with the caller. A triumphal song is produced for a brief period after a successful mating and may reinforce the mating bond to encourage the female to lay some eggs rather than find another male.
Cricket Chirps Tell Temperature
Crickets chirp at different rates depending on their species and the temperature of their environment. Most species chirp at higher rates the higher the temperature is. The relationship between temperature and the rate of chirping is known as Dolbear’s law. According to this law, counting the number of chirps produced in 14 seconds by the snowy tree cricket, common in the United States, and adding 40 will approximate the temperature in degrees Fahrenheit.
How to Catch a Cricket
If you are patient, you can sneak up on a chirping cricket. Each time you move, it will stop chirping. If you remain very still, eventually it will decide it is safe, and begin calling again. Keep following the sound, stopping each time it goes silent, and you will eventually find your cricket.