Cricket Chirping

In summer, the night air is filled with the sounds of chirping crickets. The chirps are the love songs of the male crickets hoping that the female cricket of their dreams will hear their lonely song and respond.

Insect hearing has similarities and differences with human hearing. Our ears are on the side of our head. Inside our ear is a membrane, the ear drum, that vibrates in resonance to vibrations in the air.

Female crickets have membranes that vibrate in response to sound. Their membranes respond maximally to the sound produced by male crickets. Crickets that are better at finding mates are more likely to mate and produce offspring. Crickets that cannot find mates do not produce offspring and their genes are not passed to the next generation. Every generation, those genes best enable crickets to find mates are the ones that are passed to the next generation. Over time, this leads to refinements in the sound detection organs that produce a very fine tuned system.

Unlike people, who have ears on our heads, crickets have their “ears” on their front legs. All sound detection systems are better able to determine the direction of a sound if their are at least 2 detectors and they are far apart. Thus, the ears of crickets are located on the front legs. This allows the sound detectors to be further apart. The membranes are in pits in the front legs and have directional sensitivity. They are most sensitive when directly facing the location of the sound and less sensitive as they are rotated away from the sound direction.

Directional sensitivity enables crickets to determine if the mating call is coming from the left or the right. If the sound is louder in one ear than the other, the cricket will turn its body. When the body is directly facing the location of the mating call, the response of the two detecters is equal. A mate will be found by moving straight ahead.

The next time a cricket keeps you awake at night, think of the lonely males desperately calling out their love songs and the female crickets listening in the dark. It may help you go back to sleep.
The leg of a cricket showing the location of the ear (arrow)

About jjneal

Jonathan Neal is an Associate Professor of Entomology at Purdue University and author of the textbook, Living With Insects (2010). This blog is a forum to communicate about the intersection of insects with people and policy. This is a personal blog. The opinions and materials posted here are those of the author and are in no way connected with those of my employer.
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9 Responses to Cricket Chirping

  1. Kurt says:

    My first time here and just half way through reading your latest post, I know I want to subscribe to your blog already! I love insects and I really want to know more about them!

  2. jjneallwi says:

    Welcome.
    Suggestions for topics or questions are welcome.

  3. Ryan Foley says:

    This is a very intriguing blog. I was never aware of the underlying purpose of cricket chirping. What is the percentage of crickets that do not find mates and suffer from non-reproduction of offspring?

  4. jjneallwi says:

    The percentage of crickets that do not find mates varies with the species and population density. If too high, there are not enough territories and males will compete. Larger males may mate multiple times and smaller males, not at all. Mortality is very high for many insects. The percentage that fail to mate for a variety of reasons can exceed 50 percent.

  5. Brandon Mabrito says:

    I found this entire blog post to be extremely interesting. I did not know that only male crickets chirped. I also did not know that they chirped to find a mate. If only it was that easy for humans! Now whenever I hear crickets chirping, I am going to become sad for all the lonely crickets.

    I thought it was very interesting to learn that crickets had their ears on their legs. I just assumed that their ears were on their heads, like just about every other creature. I was shocked to learn that the ears were part of the legs. That was one of the most interesting things I’ve learned in awhile.

    Anyways, this was the first post I read and found it to be fun and interesting. I love learning about insects and this blog is a perfect way for to learn more about them.

  6. Christy Larson says:

    I thought this topic was very fascinating. I had no idea crickets had ears on their legs and can determine where a mate is located by using directional sensitivity. It is neat to think how different insects can be from humans, but still have some of the same qualities like hearing sound.

  7. Candace Putnam says:

    How interesting! I always thought that all crickets chirped, whether male or female, and without a real purpose to it (other than annoying humans). Who knew it was only the males’ singing for a mate?! I’ll definitely think twice next time they frustrate me with their constant chirping. They’re probably even more frustrated trying serenade a female with their lovely songs!

  8. Kurt says:

    I have a question: there’s a male cricket in my bedroom, but i just can’t locate him. I can’t even tell if he’s to my left, right, front or back! The chirping is really loud. I need to find him and relocate him. Thanks!

  9. luminos1 says:

    bioacoustic study of grillus campestris. The new applicativ study in Romania

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