Do Crabs Sleep Upside Down? 6 Reasons Why They Could

Do crabs sleep upside down?

Have you seen your crab stay upside down before and it looks as if it’s sleeping in that position? Well, crabs are very funny creatures, sometimes they exhibit some funny behaviors that may startle you, and one of such behaviors is acting as if they are sleeping upside down. If you are reading this article, that means you want to find out if crabs do sleep upside down. Please read to the end.

Do crabs sleep upside down? Crabs do flip themselves over when they are about to sleep or Molt.

Apart from sleeping, there are many reasons why they flip themselves over.

Many species of crab could do this a lot, while some do not, for instance, species like the hermit crabs could do this most often than some other crabs.

Although am not sure their reason for turning upside down when they are about to sleep, they do it so often when they feel dizzy, especially hermit crabs.

As I mentioned above, apart from sleep, there are other reasons why crabs will turn themselves upside down.

Why Crabs Turn Upside Down

To Sleep

Sleep is what every animal does, whether during the day or at night, but methods of sleep or position of sleep differ a lot.

Some species of Crab love staying upside down when they sleep, such as hermit crabs, etc.

Although the reason why they do that is unknown, but they sometimes do it to sleep.

Sometimes to know if your crab is sleeping when they flip over is, they will tuck their eyes into their shell and expose only their legs.

So, if you crab flips over, then it may be sleeping, but not always because there are other reasons they do that too.

To Molting

Although it’s very very hard to see a crab while it’s Molting unless they don’t have any substrate, cave, etc that they could hide in while doing it.

Yes, they hide while doing it, but they often turn themselves upside down in the process.

Many crabs could do this while Molting, including hermit crabs, fiddler crabs, etc.

So, if you happen to see them turn upside down, then there is a chance that they are not sleeping, but Molting.

Molting could be very stressful and requires a lot of strength to complete, that may be the reason they do flip over while doing it.

They Could Fall Down While Climbing

Did you know that crabs could also be referred to as escape artists just like crayfish?

This is because they are very curious and like to explore their environment too, including climbing their tank to escape and explore.

Many times, they slid and fall back to their tanks and flip over in the process without having enough strength to turn over again.

When this happens, it will not be like when they sleep because they might be struggling to turn over and shaking and moving their body, etc.

So, your crab could be upside down because it fell while trying to climb or escape the tank.

For Protection

Another reason a crab might turn upside down is, that it is protecting itself from harm etc.

This is one of their protective techniques, so, they do this a lot when there are some suitable tank mates in their tanks, to keep themselves from getting eaten or harmed, they flip upside down.

Some species such as the hermit crab which has a soft shell and normally borrow shells from dead animals like snails etc do this a lot by hiding inside the shell and flipping over to be safe whenever they sense danger.

They Do This When Startled

Apart from flipping over when they sleep or sense danger, they also do it when they are suddenly started.

Out of fear, a crab, especially a hermit crab will try to hide back in its shell, and with that velocity of pulling back, the shell might lose balance and flip upside down.

This happens to me a lot, especially when I suddenly flash my torch on them, they will quickly rush back in, and because of that speed, they will lose balance and turn upside down.

They Turn Upside Down When They Die

Many aquarium animals flip themselves over when they die and some could float too.

When it comes to Crabs, they don’t normally float but turn upside down when they are dead.

This is because they have no weight, or energy in them when they die, so the water might turn them anyhow.

To know if your crab is dead while upside down, poke it with a stick or anything, and if it is not showing any sign of being alive, then it’s probably dead.

Again smell it and if the smell is not natural, then it’s gone.

How Do You Know When A Crab Is Sleeping?

Sometimes when crabs sleep, we often mistake them for being dead based on some characteristics they exhibit while sleeping such as turning upside, down, etc. So how do you tell when they are sleeping?

A crab is sleeping if it is tucked into its shell fully or partially. They will sometimes tuck their eyes inside their shell and leave only their legs or they may turn upside down.

These are some of the characteristics that crabs display while sleeping.

Although the surest way to know that they are not dead but sleeping is, they will still display signs of living by the movement of their body parts such as legs, etc.

Can Crabs Be Upside Down?

Maybe you have seen a crab lying upside down and you are curious to know if they could do that.

Can crabs be upside down? Crabs could turn upside down if they want.

There are many reasons why they do that, some they do willingly and some they don’t purposely do.

In the wild, you could see hundreds of crabs upside down because they were turned by water current or wind.

Sometimes their predictors might turn them while trying to see if they could get a nip, etc.

So, crabs do turn upside down willingly or not.

Can Crabs Turn Themselves Over?

Knowing that they could turn upside down either on their own or something pushed them to be in that position, you might be wondering if they could turn them over again on their own.

Can crabs turn themselves over? While upside down, crabs could turn themselves over if they want, either by holding onto something or turning over with their strength.

We all know that there is no how they could stay upside down forever, or they will die, so, they normally get back up after flipping over.

When a crab is upside down, it will be struggling and pulling itself to turn back over again, unless it purposely wants to say that way in the meantime.


Many species of crab could sleep upside down, and they love doing so.

Although being upside-down might not be because it’s sleeping. There are some. other reasons they stay upside down as explained above.