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6 Hermit Crab Poop Facts!

Although they are still no where near as popular as other aquatic pets, there has been a sharp increase in the number of people who are keeping hermit crabs as pets with their popularity still steadily increasing with each year that goes by.

Due to the popularity of keeping hermit crabs as pets increasing, we have also noticed a direct spike in the number of questions that we see from members of the community each month about keeping hermit crabs as pets.

One of the more common sets of questions that we have noticed people asking time and time again all relate to hermit crab poop and how to keep your tank clean with a hermit crab in it.

Due to this, we have decided to publish this dedicated article going over all of the more popular questions that we see being asked from the community about hermit crab poop in an attempt to help as many of our readers as possible who keep a pet hermit crab.

Before we go any further with our article, we want to quickly cover a piece of misinformation that we commonly see on social media about hermit crab poop.

We constantly see people saying that cherry shrimp and mystery snails will eat hermit crab poop on social media but this is not correct and neither animal will actually eat poop.

Adding either option to your aquarium will not help to reduce the amount of hermit crab poop in your aquarium and you will still have to manually remove the poop.

Do Hermit Crabs Poop A Lot?

Hermit crabs so produce a relatively high amount of poop relative to their size but this is normal when you factor in just how much detritus and algae a hermit crab will consume each day.

Due to it being much easier to remove the poop from the hermit crab from your tank than it is to remove the detritus or algae, the majority of people choose to keep their hermit crab as it does result in less tank maintenance being required from you.

The vast majority of people who keep an aquarium will have a weekly servicing routine where they use a decent gravel vaccum to clean the substrate of their aquariums anyway.

This will usually be enough to clean all of the hermit crab poop out of the tank without it having a chance to build up and cause any problems with the water quality in your tank.

Although hermit crabs do produce a surprising amount of poop, they still produce less than something like a nerite snail that usually serves a similar practical purpose in your tank of consuming algae and detritus.

Due to this, you may even be able to get away with carrying out your aquarium servicing with your gravel vacuum once every two weeks as hermit crab poop will take a while to build up, especially in larger tanks.

What Does Hermit Crab Poop Look Like?

The poop of a healthy hermit crab will usually be about the size and shape of a penny with it potentially having a thing string coming off it too.

Hermit crab poop can also be black, brown, green or white depending on what the hermit crab has been eating with all four colors being healthy for the crab depending on its diet.

Due to the majority of hermit crabs having a mixed diet of detritus and algae, their poop is usually black or brown and this is what the majority of people will see if they keep a pet hermit crab.

If there is not much detritus, especially discarded fish food in the tank and your hermit crab has to eat lots of algae then its poop can be a green color.

Although some people worry if their hermit crabs poop is white, offering a hermit crab some cuttlebone to keep its shell healthy is normal and with cuttlebone being white, it can result in white hermit crab poop depending on how much cuttlebone the crab eats.

With most peoples hermit crab poop being black or brown, it can make it a little difficult to see if you use a soil substraite for your tank. It will usually be much easier to see on most other substrate types though and will still easily be cleaned up using a gravel vacuum.

Do You Have To Clean Hermit Crab Poop?

You will have to clean hermit crab poop out of your aquarium yourself to prevent it from building up to dangerous levels where it can start to cause degradation in your water quality.

Thankfully though, most people will be able to clean their hermit crab poop out of their tank as a part of their normal tank maintenance before it gets to these levels anyway using a simply gravel vacuum.

As we touched on back at the start of the article, some people on social media do claim that cherry shrimp and mystery snails will eat hermit crab poop but this is not correct.

Neither cherry shrimp or hermit crabs will knowingly eat hermit crab poop and although they may mistake it as food at times, they will quickly spit it out once they realize that it is not food.

Some people have tried to use plants in their aquarium in way where they will be able to draw as much nutrients from your hermit crab poop as possible too but this rarely works.

It usually takes far too long for the plants to draw enough nutrients from the crab poop to make it worth the time and effort. This is why using a gravel vacuum is the more common method of removing hermit crab poop from your tank.

How Do You Clean Hermit Crab Poop?

The quickest, easiest, and cheapest way to clean hermit crab poop from your aquarium is to use a simply gravel vacuum as a part of your weekly aquarium servicing.

It will effortlessly clean out all of the hermit crab poop along with any other poop from other animals in the tank with detritus and some algae being removed at the same time.

Most of our readers will be able to get away with simply using a decent gravel vaccum and being able to keep their costs as low as possible when looking to clean the hermit crab poop from their aquarium.

There are some electric gravel cleaners on the market these days too but in reality, they don’t actually save you that much time.

We have also seen a number of aquarium pumps that claim to be able to help remove poop from your tank but they tend to perform poorly.

We would also avoid any guides that you find online about how you are able to convert your current tank pump to be able to remove hermit crab poop too as you will usually end up breaking your pump.

Do Hermit Crabs Poop And Pee In Their Shells?

Hermit crabs do poop and pee in their shells but their pee usually washes out with the tank water quickly and hermit crabs throw their poop out of their shells using their front legs as soon as they are done.

This is why you can find hermit crab poop in random places of your tank due to the crab throwing it and then the tanks water flow catch it and depositing the poop on top of your plants.

You have to keep in mind that a hermit crab is surprisingly vulnerable when compared to other types of crab and they have to keep the shell that they occupied as clean as possible.

Removing their poop and pee from the shell as fast as they can helps to prevent the build-up of bacteria in their shells and reduce the chances of any health problems taking hold.

In rare situations, you may realize that there is some hermit crab poop hanging out of the shell that your hermit crab occupies.

If you do notice this then we would highly recommend that you give your hermit crab a helping hand and manually remove the poop from their shell for them.

Do Hermit Crabs Eat Their Own Poop?

Although some people on social media do claim that hermit crabs will eat their own poop, this is not correct and hermit crabs are surprisingly clean animals considering they feed on detritus.

This is why you need to manually remove the hermit crab poop build up from your tank once a week or every other week as it is hard to get rid of it in any other way.

As we touched on above when talking about people saying that cherry shrimp and mystery snails will eat hermit crab poop, we feel that the misunderstanding about hermit crabs eating their own poop comes from them accidentally mistaking poop for food. As soon as they realise that it is not food, they usually spit it out quickly.

Additionally, hermit crabs may use their claws and legs to move poop away from their preferred locations in the tank making it look like their claws and legs are dirty with poop.

This may result in some people thinking that their hermit crab has been eating poop and that is why it is on their claws and legs but their hermit crab has just been doing a little clean up in the tank.


That brings our article going over hermit crab poop to an end. We hope that our readers have found our article helpful and that we have been able to help you better understand some of the more community questions that we see the community asking. On top of this, we have also tried to explain why some of the common misinformation on social media about hermit crab poop is incorrect as we constantly see it being repeated over and over again.