In my cricket farm I keep around 100.000 live crickets (Acheta Domesticus). Can you imagine how it sounds to hear that many crickets chirping at once? It’s like an orchestra!
There are few reasons why cricket do chirp. Main chirping reasons:
- To attract females
- As a triumph after successful mating
- To warn another male crickets to stay away
A science term for a cricket produced chirping sound is called stridulation. It is an act of producing sound by rubbing together certain body parts (in this case – wings).
Only male crickets do the chirping. Also, male cricket is capable to product chirping only when fully mature. If you’re interested to know more about when crickets start to chirp, you can check my post about crickets’ life cycle.
A chirping cricket is very popular in Hollywood movies to represent awkward situations, silence or emptiness in a funny way.
Further in the post we will analyze deeper why do crickets chirp, but let’s begin with an explanation how do crickets do it.
How Do Crickets Chirp?
Crickets make sounds by rubbing the wings against each other. Mature cricket has a pair of hind wings and a pair of fore wings. Fore wings’ one of the purpose is to protect hind wings. Cricket’s hind wings are longer and more fragile.
When both pairs are being rubbed against each other, a chirping sound is produced.
Interestingly, House Crickets (Acheta Domesticus) and many other cricket species have evolved wings enough to be able to reproduce, but wings are not evolved enough for crickets to use them for flying. The best crickets can do is to jump and by leveraging the wings slightly increase the length of jumped distance.
As a cricket farmer I often hear false statements that crickets make sound by rubbing their legs. That is not true. My guess is that people usually confuse themselves by thinking that cricket and grasshopper is that same insect. Well, that’s simply not true.
I have made a post where I compared cricket vs grasshopper. If you are interested, give it a read.
Fact: only male crickets can chirp. In contrary, female crickets are silent insects.
Let’s go further to see how exactly cricket’s noise is being produced from the wings.
There are hundreds of different cricket species. Different species produce slightly different sound which to human ear is sometimes possible to distinguish (if you have something to compare with). Below you will find different crickets; species sound examples.
Male crickets under the wings have particular row of teeth. Depending of species, count of teeth can vary from fewer than 10 to 1300 teeth (source).
Here’s an example how teeth looks on the wings of a field cricket (source):
Cricket’s chirping sound frequency depends how fast wings are rubbed, but the average frequency is 1.5 – 10 kHz.
A cricket sound itself appears when teeth from separate wings are rubbed one against each other. Between teeth you can see empty gaps. Those are silence gaps followed by chirping pulse sound.
If we would record a chirping cricket and slow the record, it would look something like this.
The frequency of those chirping sets (i.e. chirping impulse and silence gap) can vary depending on species. Cricket’s chirping frequency can be as low as once per 3 seconds to more than 200 times per second (e.g. Malaysian Gryllotalpine).
Here is an audio of a field cricket. This is the cricket which we all hear in the fields during warm summer nights (source):
In comparison, here’s how a Jamaican Field Cricket (Gryllus Assimilis) sounds like. As you can notice, the frequency is much lower comparing to a field cricket (source):
And this is the sound of Allard’s Ground Cricket (Allonemobius Allardi) (source):
Why Do Crickets Make Sound?
When you hear a cricket chirping, probably you noticed that they chirp quite much and for a long time. As mentioned previously, there are only 3 main reasons why male crickets chirp.
1. To attract females. Crickets are relatively small insects. So, for a female cricket to find male cricket in a grass field or a forest is quite hard task. I will not even mention how hard it is when females have to do this in the dark!
A male cricket starts chirping as loud as he can to make sure that a female cricket hears it if she is nearby. If female cricket hears it, she instinctively tries to identify from where the sound comes, so she could move the correct way to reach the male.
When female comes close, male cricket usually decreases chirping volume, so chirping becomes softer. A softer sound means that male cricket is inviting female to start mating.
But what if a female cricket hears two or more different male crickets chirping in the area?
Well, I have heard a theory, that by the chirping sound, female cricket can identify which of the chirping males is the biggest. A female will always by instinct select the male which produces the loudest sound (to continue the best possible genes in the generation).
2. As a triumph after successful mating. A mating happens when female cricket crawls on a male cricket, who will spread his sperm to impregnate the female. One study shows, that a female cricket obtains the sperm from few different male crickets and then decide which sperm to use for the fertilization (source).
So, after the mating, the male will begin chirping as well, to imply that female cricket should choose his sperm .
3. To warn another male crickets to stay away. Crickets are watchful insects (as the whole fauna in nature). Every male cricket has its own territory which they guard carefully. Crickets are popular insects and they spread exponentially. Hence, it‘s normal that in few square yards (meters) there can be few male crickets.
If it happens that two male crickets collide, then they start to chirp as well. Usually one of the crickets will be louder. Meaning, often male crickets will finish the fight before it even started, because in most of the cases the more silent cricket will move away and louder cricket will be the winner (natural selection and hierarchy).
How Do Crickets Hear Chirping Sound?
If you have read up till here, it means you have already learned that both cricket genders need to hear other crickets chirping sound.
- For female crickets to find male crickets for mating.
- For male crickets to avoid fights with stronger males.
Crickets have ears in their legs.
Crickets have ears located slightly below the knees of front legs. Crickets’ ears work in same way as human ears – i.e. by receiving vibration.
After receiving the sound in the ear, it is pushed further through the chambers inside the legs. Chambers are connected from both legs. It allows cricket to identify which way a sound is coming from.
Quite extraordinary, huh?
Where Do Crickets Chirp?
In terms of physical location, a male cricket chirps basically anywhere, where they hang out. You can find crickets in grass fields, forests and meadows.
It’s not unusual to hear crickets inside people’s homes. It most of the cases it happens when during cool nights crickets are looking for warmer spots. Also, from my experience as a cricket farmer – if there’s a crack in a wall, floor or ceiling, a cricket will get there. Good luck taking it out from there!
So, crickets can chirp anywhere: outside in the fields/forests and inside in various buildings/houses/flats.
Though, important to note that crickets will chirp only if weather conditions are right for them.
Do Crickets Chirp At Night?
Crickets are nocturnal insects. It means that they stay active during night and during daytime they are resting.
Though, from my practice of raising crickets, I couldn’t say that during day time crickets are inactive or become significantly slower. In my farm I keep automatic lighting (14 hours it‘s dark and 10 hours light are on). I use the lighting to replicate daytime light as much as possible to make crickets feel as in nature.
I have noticed that when I turn on the lights after “night time”, crickets are as active as during night time. Also, when lights are on for few hours, crickets are still very active (chirping, jumping around, mating, eating and drinking). From my experience I didn’t notice a big difference in crickets’ activity at day time vs night time.
However, crickets in captivity and nature may act differently.
In theory, crickets don’t chirp or chirp as little as possible during day time, because chirping sound attracts many predators. Crickets don’t have good enough defense mechanism from predators (except for jumping capabilities).
Crickets, same as worms, are one of the easiest catches. They are a target by almost all the birds and reptiles (lizards especially). So, at the same time cricket’s chirping can be a curse and a blessing. A blessing, because by chirping a male cricket is capable to find a female and continue the generation. A cruse, because predators can find a male cricket easier and eat it.
Hence, it makes more sense for male crickets to chirp during night time to decrease chances to become a prey.
Also, we’re used to hear cricket sounds during night time during those long warm summer nights, because at night time majority of flora is sleeping. So, there are not too many sounds happening at night time besides crickets chirping or random own hooting.
Crickets also chirp at day time, but during the day we’re distracted by all the other sounds in our surrounding. That is why we think that crickets chirp at night only.
Try to go in forest or empty grass field in a calm country side during daytime. Try to hear a cricket chirping. You will be surprised how many you will hear!
Why Do Crickets Chirp In Warm Weather?
Appropriate ambient temperature is essential for a male cricket to be able to chirp.
Disclaimer: How fast cricket chirps depends mainly on the ambient temperature (not on day or night time).
Crickets are Poikilotherms, which means that crickets’ body doesn’t keep the warm as humans or animals. Hence, cricket’s body temperature is dependent on ambient temperature.
Ideal ambient temperature range for House Crickets is 81-91°F (27-33°C).
At lower ambient temperatures crickets will chirp less, because their metabolism will decrease. It means that crickets’ body tries to adapt to decreasing temperature and waste as little energy as possible, so they could survive as long as possible. These actions are not intentional by crickets, it happens naturally.
Why, you ask? Well, that’s how nature works.
If temperature drops below 59°F (15°C) you can notice significant decrease in movement for crickets (crickets entering hibernation stage). At this temperature crickets are not chirping anymore, because rubbing wings to create the sound required very much energy.
In contrary, higher temperature = more active crickets. If temperature is above 91°F (33°C) crickets will significantly increase their chirping speed. Also, I should mention that chirping requires crickets to release a lot of energy, which is finite for these small insects. It means that if male cricket chirps faster than usual for a long time, it will die faster.
If you’re interested about crickets lifespan, check my other post about how long do crickets live.
The Cricket as a Thermometer: Dolbear‘s Law
Crickets‘ chirping frequency depends on ambient temperature. Those folks can be used as a thermometer to find what is current temperature. You can do it only by listening to the chirping! Interested? Read further.
In 1897, a scientist Amos Dolbear published an article where he identified correliation between ambient temperature and the rate at which crickets chirp.
Dolbear came up with a formula, which is now known as Dolbear‘s Law.
Dolbear‘s formula (Fahrenheit):
Dolbear’s formula (Celsius):
When Dolbear made the article, he didn’t mention with which cricket species the formula works. As I mentioned previously, there are hundreds of crickets’ species and their chirping frequency varies from once per 3 seconds to 200 times.
However, scientists later confirmed that this formula can be applied to a field cricket (the one you hear outside during warm summer nights). Despite, cricket’s chirping frequency depends on more factors than solely temperature. So you shouldn’t take this formula for granted.
By the way, there’s a simpler Dolbear’s formula which you can remember when you will want to show off to your friends when you will be hanging out somewhere in nature and hear a cricket chirping! Here it is:
For example, if within 15 seconds you hear a cricket chirping 30 times, then you need to add 40 + 30. Result: if cricket chirps 30 times per 15 seconds, approximate temperature is 70°F.
For example, if within 8 seconds you hear a cricket chirping 20 times, then you need to add 5 + 20. Result: if cricket chirps 20 times per 8 seconds, approximate temperature is 25°C.
Why Crickets Are Not Chirping?
Male crickets are not always making sounds. There can be few reasons why crickets are quiet:
- Temperature is too low for a cricket. As mentioned previously, crickets need ambient temperature to be above 59°F (15°C) for it to start chirping at least a little bit. Lower temperature results cricket to slow metabolism too much and cricket starts entering the hibernate state.
- Cricket is hiding from predator. Crickets are very cautious insects. If you approach a cricket with fast movement you will notice that cricket will get quiet instantly. Also, you will notice that they will try to jump to safety (i.e. hide) as soon as they identify unknown sounds. Any unknown sound/movement crickets will consider as a predator, so without exception they will instantly try to hide if you approach them fast.
- Cricket is a female. Only male crickets chirp by rubbing wings against each other. Female crickets also have wings but they are not being used to make sounds.
- Cricket is too young. Make crickets start chirping only after they shed their exoskeleton last time (molting happens ~7 times in total). After last shedding, cricket’s wings evolve and he begins the chirping.
- Cricket is sleeping. Not much to comment on this one 🙂
To summarize: next time when you will hear a cricket chirping, I am confident that you will be able to spread some facts why and how do crickets chirp!