You probably noticed that during warm summer nights you can often hear chirping crickets. What you probably didn’t notice is that during cooler weather crickets stop chirping. Why? Do crickets actually die in cold weather? Let’s figure it out.
Different cricket types can have different freeze tolerance. In general, crickets do not survive winters. They all die as their metabolism rate decreases too low and they stay in dormant state for too long. Studies have shown that some cricket species can survive for a week if kept in 18°F (-8°C). If crickets stay under minus 18°F (-8°C) for 24 hours, they will most probably not recover.
OK, we have established that appropriate temperature is very important for crickets. Let’s see how it impacts where crickets can actually live.
Where Can I find a Cricket?
Crickets can be found in all continents except Antarctic. They belong to Orthoptera order and are part of Gryllidae family tree, which has over 4.800 species of crickets or similar-to-cricket insects.
Few popular crickets’ species:
- Camel crickets
- Cave Crickets
- House crickets
- Mormon crickets
- Field crickets
- Jerusalem Crickets
Different species which can live in different geographical areas, though, all of them like warm weather which is vital for crickets to be able to reproduce.
Most popular crickets are House crickets (Acheta domesticus) and Field Crickets (Gryllus campestris). These are the ones which we usually hear outside chirping when weather is warm during summers.
Some crickets prefer more dry areas while others like humid locations to live in. Though, without exception all crickets will look for humid areas/soil to lay the eggs in.
Only female crickets lay eggs (~5-10 per day; ~100 max per life time). Only male crickets chirp.
Generally, crickets can live anywhere. For example, big chances that you will find crickets in these locations:
- Agricultural fields
Crickets can live almost anywhere as they also are capable to eat almost anything. However, appropriate temperature is crucial.
What Temperature Is Ideal for Crickets?
Crickets are Poikilotherms. It means that these insects do not keep body warmth. Their body temperature is solely dependent on ambient temperature. For crickets to be able to reproduce the optimal temperature is 80-90°F (27-32°C).
I myself have a small commercial cricket (Acheta domesticus) farm. I always make sure that temperature doesn’t drop below 80°F (27°C). For crickets’ eggs I always try to maintain temperature at least 86°F (30°C). Under optimal temperature and humidity (100%), crickets’ eggs should hatch within 11 days. I accomplished it when I kept the soil and the container above 88°F (31°C) at all times.
However, in captivity crickets have a little bit different habitat than in nature. In captivity, temperature is always staying on the same level, which is around 80-90°F (27-32°C), approximately. It means that crickets’ life cycle is optimal in term of temperature. A house cricket fully matures in 35 days if temperature is 90°F (32°C).
In contrary, nature has day and night cycles. It means that temperature can fluctuate significantly every ~12 hours or so (depending on location). That is why a cricket’s life cycle in nature usually extends due to temperature fluctuations.
A cricket’s body functions in a way that if temperature is 80-90°F (27-32°C), then its metabolism rate is sufficient and crickets grow at the optimal pace.
Metabolism is term which means a set of chemical reactions which keeps an organism alive.
For example, if temperature increases higher than 90°F (32°C), then cricket’s metabolism rate will increase.
What will that mean for a mature male cricket? Well, male crickets have one life-long task – chirp with their wings to attract female crickets to mate. So, if temperature increases in male crickets’ environment, then the chirping speed will increase, because metabolism rate increases as well.
If you’re interested to know more about crickets’ chirping, checkout my other post about why do crickets chirp.
In contrary, crickets’ metabolism rates will decrease if temperature drops. For example, in environment where temperature is 59°F (15°C) or lower, you can easily notice that you will not hear any crickets chirping outside. That is because crickets start to go into hibernation state.
Instinctively, crickets try to save as much energy as possible when temperature drops. That is how nature works – i.e. if crickets feel the temperature is decreasing, then they don’t care about reproduction and mating. They just want to survive as long as possible, so they save their energy. Chirping requires a lot of energy, hence, crickets automatically stop doing that if temperature is ~59°F (~15°C) or below.
There are no scientific researched made to confirm the exact temperature when crickets stop chirping. I am certain that temperature levels for chirping are different for various cricket types. However, from my experience as a cricket farmer, I have noticed that House Crickets stop chirping if temperature drops to approximately ~59°F (~15°C).
So, the more temperature drops, the less energy crickets try to use. Crickets save energy not only when discontinuing the chirping. This is how crickets adapt to dropping temperature and energy saving mode:
- Stop chirping
- Stop jumping
- Slow down or stop the movement
What Temperature Kills Crickets?
There is a temperature threshold when crickets’ metabolism rate drops so much that they instinctively start to hibernate and reach dormant stage. If crickets stay for too long in dormant mode, they are not capable to recover and die.
I did some research and found some interesting information about the temperature levels about crickets’ dying and survival rates.
Crickets can freeze when temperature drops below 32°F (0°C). For crickets, same as humans, bodies mainly consist of water. It means that if temperature drops to water freezing level, then water inside crickets’ bodies freeze as well. That is called internal ice formation. Meaning, if crickets freeze and ice forms in their bodies, they are still capable to recover from dormant state and continue living.
However, there are limits how long crickets can stay frozen and then recover.
Currently it is not known to scientists exactly how biological mechanisms work inside crickets that control crickets’ recoveries. Though, we know a little bit about the freeze tolerance to crickets (i.e. how long can crickets be frozen under various temperatures and still recover when temperatures rise).
Study Research #1: Crickets’ Freeze Tolerance
At the university of Western Ontario an experiment was performed during which was tested what freeze tolerance crickets can keep up with.
A Spring Field cricket (Gryllus veletis) was selected for the testing. Crickets were frozen to various temperatures for different time periods. Results showed that majority of crickets survived as low as 10°F (-12°C) after they were kept in freezer for 1.5 hours. Meaning, after 1.5 hours in 10°F (-12°C) crickets unfroze, their metabolism rate increased and eventually they were able to fully recover and live as usual.
Other batch of crickets were frozen and kept under 17.6°F (-8°C) temperature for 7 days. Interestingly enough, crickets were able to recover after 7 days of being frozen as well! Source.
Study Research #2: Crickets’ Freeze Recovery Time
To evaluate freeze tolerance for insects there’s a term called cold-induced paralysis (chill-coma).
Here is why a term is called “cold-included paralysis”. From my experience: In my cricket farm I usually see that if cricket is taken from warm farm temperature to 50°F (10°C) or lower, then after 10-20 mins their metabolism rate drops significantly and they stop any movement, except their legs start to twitch, which is a symptom of paralysis.
In Stanford University a research was made to identify how long does it take crickets to recover after they are exposed to 32°F (0°C) for various time periods.
This time the Fall Field cricket (Gryllus pennsylvanicus) was selected for the test. This cricket is a very close relative to a house cricket which we are usually hear outside.
The results showed that after crickets were kept in 32°F (0°C) for less than 5 hours, it took less than 10 mins to recover in a warm environment. Crickets, which were kept in 32°F (0°C) for 5-12 hours, took 10-15 minutes to recover. What is interesting, that recovery time reached a plateau after 12 hours. Meaning, that it didn’t matter if crickets were kept in 32°F (0°C) for 12 or 24 hours, they still recovered on average within ~15 mins.
However, crickets that were kept in 32°F (0°C) for over 24 hours, the recovery time started to vary significantly (sometimes even to ~40 mins).
This testing lasted 45 hours. There are no results to indicate if crickets were still able to recover from 32°F (0°C) after staying in such temperature for over 2 days.
What Temperature Kills Crickets In Captivity?
As you can see from the researches mentioned above, crickets are quite good at recovering even when kept in as low as 10°F (-12°C) temperatures for few hours.
As a cricket farmer I follow few main rules when it comes to harvesting crickets and freezing temperatures.
I have a 300 liters freezer. When freezer is half full, I adjust the temperature to -22°F (-30°C) and fill harvested crickets till the top. Here’s how it looks.
I always make sure that the freezer is setup to around -22°F (-30°C) before I start putting crickets in the freezer. The reason I do this is that crickets contain warmth inside their bodies. Hence, a freezer cannot maintain the sufficiently low temperature and it starts to slowly warm if I fill up the whole freezer with new crickets. For that reason, I always setup a freezer to the lowest possible temperature before crickets are added.
After crickets are added, it takes around ~30 mins and temperature increases to 32°F (0°C) . Then it stays around 32-23°F (0 / -5°C) C for few hours. After 24 hours temperature drops back to -22°F (-30°C) as crickets have released all the warmth to the atmosphere. At that point I setup standard temperature to -6°F (-21°C) which is optimal to keep frozen crickets and make sure that they will not wake up after crickets are taken further on the production line.
To summarize: crickets are interesting insects which are capable to survive under extreme cold conditions. Scientists up to this date are still trying to figure out exactly how crickets can recover from chill-coma. Though, crickets can recover only if frozen for a limited amount of time. What is clear and safe to say is that crickets, at least a House Cricket (Acheta domesticus), will die without capability to recover if temperature drops below -6°F (-21°C) for a longer than 36 hours.