10 Fascinating Facts About Crickets

How They Hear, Make Music, and Tell Us the Temperature

House cricket.
Breeding house crickets is big business. Getty Images/Paul Starosta

True crickets ­(family Gryllidae) are probably best known for their incessant chirping on late summer evenings. Most people can recognize a house or field cricket, but how much do you know about these familiar insects? Here are 10 fascinating facts about crickets:

Close Cousins of Katydids

Crickets belong to the order Orthoptera, which includes grasshoppers, locusts, and katydids. While all these insects share traits with crickets, katydids are their closest cousins. Crickets and katydids feature long antennae and ovipositors (tubular organs through which they deposit eggs), are nocturnal and omnivorous, and use similar methods to make music.

Masterful Musicians

Crickets sing an impressive variety of songs, each with its own purpose. A male's calling song invites receptive females to come closer. He then serenades the female with his courtship song. If she accepts him as a mate, he might sing a song to announce their partnership. Male crickets also sing rivalry songs to defend their territories from competitors. Each cricket species produces a signature call, with a unique volume and pitch.

Rubbing Wings Makes Music

Crickets produce sound by stridulating, or rubbing body parts together. The male cricket has a vein at the base of his forewings that acts as a file or scraper. To sing, he pulls this ridged vein against the upper surface of the opposite wing, causing a vibration amplified by the thin membrane of the wing.

Ears on Front Legs

Male and female crickets have auditory organs on their lower forelegs, oval indentations called tympanal organs. These tiny membranes are stretched over small air spaces in the forelegs. Sound reaching the cricket causes these membranes to vibrate. The vibrations are sensed by a receptor called a chordotonal organ, which turns the sound into a nerve impulse so the cricket can make sense of what it hears.

Acute Hearing

Because the cricket's tympanal organs are so sensitive to vibrations, it's remarkably difficult to sneak up on a cricket without it hearing you coming. Have you ever heard a cricket chirping and tried to find it? Every time you walk in the direction of the cricket's song, it stops singing. Since the cricket has ears on its legs, it can detect the slightest vibration created by your footsteps. The best way for a cricket to avoid predators is to stay quiet.

Chirping Can Be Hazardous

Although a cricket's keen sense of hearing can protect it from larger predators, it's no protection against the sly, silent parasitic fly. Some parasitic flies have learned to listen for a cricket's song to locate it. As the cricket chirps, the fly follows the sound until it finds the unsuspecting male. Parasitic flies deposit their eggs on the cricket; when the larvae hatch, they ultimately kill their host.

Counting Chirps Reveals Temperature

Amos E. Dolbear, a Tufts University professor, first documented a relationship between the rate of a cricket's chirps and the ambient air temperature. In 1897, he published a mathematical equation, called Dolbear's Law, that enables you to calculate the air temperature by counting the number of cricket chirps you hear in a minute. Since then, other scientists have improved on Dolbear's work by devising equations for different cricket species.

Edible and Nutritious

Much of the world's population eats insects as part of their everyday diet, but entomophagy, as the practice is known, isn't accepted as readily in the U.S. But products such as cricket flour have made eating insects more palatable to those who can't bear to chomp on a whole bug. Crickets are high in protein and calcium. Every 100 grams of crickets you consume provides almost 13 grams of protein and 76 milligrams of calcium.

Revered in China

For more than two millennia, the Chinese have been in love with crickets. Visit a Beijing market and you'll find prize specimens fetching high prices. In recent decades, the Chinese have revived their ancient sport of cricket fighting. Owners of fighting crickets feed their prizefighters precise meals of ground worms and other nutritious grub. Crickets are also prized for their voices. Cricket singing in the home is a sign of good luck and potential wealth. So cherished are these songsters that they are often displayed in the home in beautiful cages made from bamboo.

Breeding Is Big Business

Thanks to the demand created by owners and breeders of reptiles, which eat crickets, cricket-breeding is a multimillion-dollar business in the U.S. Large-scale breeders raise as many as 50 million crickets at a time in warehouse-size facilities. The common house cricket, Acheta domesticus, is raised commercially for the pet trade. In recent years, a deadly disease known as cricket paralysis virus has devastated the industry. Crickets infected with the virus as nymphs gradually become paralyzed as adults, flipping onto their backs and dying. Half the major cricket breeding farms in the U.S. went out of business because of the virus after losing millions of crickets to the disease.

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