How and Why Crickets Sing

Recently I had the pleasure of supply teaching a most wonderful grade 2 class for a 40 minute block of time for three consecutive days. I spent time in three separate classes in those three afternoons, working on 'Integrated Literacy'. The grade 2 class had been working on exploring a number of Eric Carle picture books. If you have read them then you know he writes often about animals and has written a fair number concerning insects. "The Very Grouchy Ladybug", "The Very Hungry Caterpillar", "The Very Quiet Cricket" are a few of his titles. The book I examined with these children was, as is probably evident from the title of this hub, "The Very Quiet Cricket".

We chanted lines from a cricket poem and discussed characteristics of insects before I read the story to this attentive audience. The cricket in question was a newly hatched one who when approached by various insects attempted to talk back to them but until the story's end was unable. As I read the story, I stopped at various parts and asked them questions, one of which was, "How do crickets chirp.?" I was amazed by their answers. Some said they used their wings while others suggested it was their legs that were used as bows to make their music.

My memories from past biology classes told me that contrary to Eric Carle's suggestion that it was the wings, it was in reality the legs that caused the chirp of the cricket. Since my recollection differed from the author's suggestion, I told the class that I would research the topic of cricket chirping and return the next day with an answer. As I began my research at home, I thought, "Why not make this a hub?" I recently created a similar hub on, "How Flies Fly". Read on to discover, "How Crickets Chirp."

To many, the summer evening chirping of crickets is musical, while to others, it is noise preventing blissful sleep. In China, crickets singing in the home is a sign of good luck. Crickets singing in my home are hunted by my three hungry felines! Ummm, extra protein for them. Whether one thinks of them as musical or annoying, one has to wonder how these tiny insects produce and project such a powerful song.

Not all cricket species chirp, but in those with the ability, only the males are able to do so and they do so only at night, resting during the day. In order to hear and respond to the chirping, both males and females have "ears" located below the knee in their front legs. Although to some humans their song is beautiful, male crickets have a specific survival reason for chirping. Male crickets chirp for three important reasons:

• to attract a mate: the female will respond only to the unique sound of a male from her own species;
• to establish their territories: within which they hope to attract mates;
• to defend their territory against competing males: so to ensure more mates for themselves.

Crickets produce sound by rubbing their wings together. A thick, ridged vein which acts as a file, is found at the base of the forewing, The upper surface of the forewing is hard and acts like a bow of a violin. When the cricket seeks a mate or needs to defend his territory, he lifts his wings and pulls the file of one wing across the scraper of the other. The thin membrane of the wings vibrate, amplifying the sound. Stridulation is the name given to this method of producing sound.

Different songs are produced by the male cricket for different reasons:

• a song to entice females closer can be heard for up to a mile away;
• once the female is close, the male switches to a courtship song to convince her he is the right 'man';
• in some cases, the male will sing a post-copulation song to celebrate his victory with the female.

Crickets are more active chirpers in warmer weather. They won't be heard chirping if the temperature is below 55°F. A few interesting facts about crickets and their chirping:

• the Japanese have kept crickets as pets for centuries; thousands of these suzumishi are sold in tiny bamboo cages every summer to help take people's minds off the heat;
• to determine the temperature in Fahrenheit, count the number of cricket chirps in 14 seconds and add 40.

The next day the class had not forgotten my promise and I reported my findings to them a little sheepish that I had been wrong. However, whether their song inspires or annoys, the tiny cricket and its chirp are a marvel of nature. I will listen with new awareness next summer while sitting on my back porch relaxing under the stars.