Crickets are insects somewhat related to grasshoppers and more closely related to katydids They have somewhat flattened bodies and long antennae. There are about 900 species of crickets. They tend to be nocturnal and are often confused with grasshoppers because they have a similar body structure including jumping hind legs.
Crickets do not rub their hind legs together to chirp. The left forewing of the male has a thick rib which bears 50 to 300 ridges. The chirp, which only male crickets can do, is generated by raising their left forewing to a 45 degree angle and rubbing it against the upper hind edge of the right forewing, which has a thick scraper. This sound producing action is called stridulation and the song is specific to each species.
There are four types of cricket song. 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 is a very quiet song. An aggressive song is triggered by receptors on the antennae that detect the near presence of another male cricket and a copulatory song is produced for a brief period after successful deposition of sperm on the female’s eggs.
Crickets chirp at different rates depending on their species and the temperature of their environment. Most species chirp at faster rates the higher the temperature is. The relationship between temperature and the rate of chirping is known as Dolbear’s Law. In fact, according to this law, it is possible to calculate the temperature in Fahrenheit by adding 40 to the number of chirps produced in 15 seconds by the snowy tree cricket common in the United States.
To hear the mating call of other crickets, a cricket has ‘ears’ located on its knees, just below the joint of the front legs. Their auditory sensation is mediated by tympanic membranes located in their knees.
Crickets are popular as a live food source for carnivorous pets like frogs, lizards, tortoises, salamanders, and spiders. Feeding crickets with nutritious food in order to pass the nutrition onto animals that eat them is known as gut loading. Crickets are also eaten by humans in some African and Asian cultures. They are often considered a delicacy.
Crickets are popular pets and are considered good luck in Asia, especially China where they are kept in cages. It is also common to have them as caged pets in some European countries.
The singing of crickets in the folklore of Brazil and elsewhere is sometimes taken to be a sign of impending rain or of a financial windfall. In Caraguatatuba, Brazil, a black cricket in a room is said to portend illness, a gray one money, and a green one hope. In Alagoas state, northeast Brazil, a cricket announces death, thus it is killed if it chirps in a house. In Bahia, a constantly chirping cricket foretells pregnancy, but if it pauses, money is expected. The mole cricket is said to predict rain when it digs into the ground.
In Barbados, a loud cricket means money is coming in, hence, a cricket must not be killed or evicted if it chirps inside a house. However, another type of cricket that is less noisy forebodes illness or death. In Zambia, the Gryllotalpa africanus cricket is held to bring good fortune to anyone who sees it.
In English speaking comedy, the sound of crickets may be used to humorously indicate a dead silence when a response or activity is expected. For example, if a comedian in a TV show tells a bad joke, instead of the audience laughing, crickets may chirp.
Similarly on political blogs, writers may use the concept of crickets chirping in a rhetorical sense to signal that the writer believes that he or she has made a point that a hypothetical opponent cannot answer. The space that would have been occupied by the nonexistent answer is instead occupied by the symbolic word *crickets* to symbolize this silence.
The Walt Disney corporation has used a number of notable cricket characters in their animated movies through the ages. Most of these characters represent good. For example, in the movie Pinocchio, Jiminy Cricket is honored with the position of the title character’s conscience.