A basic care guide for hermit crabs

There are many vital parts to keeping your hermit crabs alive, it seems impossible to list them all in one place.

To house your new pets, a glass aquarium is best. Please allow a minimum of 45-60 litres per crab. Crabs are best kept in groups! A lid is essential.


Heating can be provided using a reptile heat mat accompanied by a thermostat to regulate temperature. Stick the heat mat to the back of the aquarium. Do not place it underneath.

Both saltwater and freshwater pools are required. Treat any tap water with a crab-safe water conditioner. For saltwater pools always use a good quality marine grade salt. Pools should be kept clean and fresh by either changing every 2-3 days or adding an aquarium air-stone or filter. Please note if you are using a filter or air stone the water will still need to be changed once a week. Crabs should be able to fully submerse themselves in pools whilst having access to climb in and out.

Humidity comes hand in hand with the two above. Keep it at a stable 75-80%. You should avoid misting the enclosure as this encourages the growth of mould and bad bacteria. Sphagnum moss soaked in some treated tap water can help raise the humidity and adding more ventilation can help lower it.

Substrate – this is the term used to describe the bedding you use in the enclosure. The only substrate we recommend is a 5:1 ratio of play sand and eco-earth mixed together. Consistency wise it should be in between wet and dry. Damp enough to hold its shape, dry enough to not be considered wet. It is essential that you provide at least 8” of substrate. This is essential for crabs during the moulting process. Moulting is when a crab sheds it’s exoskeleton in order to grow. They do this in the privacy of a burrow dug into the substrate – some crabs often being down for months at a time. Without the correct depth of substrate your crabs are at risk of being disturbed, or forced to moult on the surface. If a crab fails to moult, it can lead to severe deformity or death.

Now on to the fun part! Once you have the basics sorted you can start to focus on the aesthetics. Hermit crabs love to climb. Cork bark and bogwood are great choices for creating a natural and interesting environment for your crabs to explore. Artificial plants suitable for aquariums and reptiles are also an excellent way to add some much-needed colour and coverage.

Make sure you give your crabs somewhere to hide if they feel the need to. Coconut huts are a popular choice alongside reptile caves. Please make sure that any woods or materials you introduce are safe and not coated in toxic plastics.

Now then, on to the topic of food… Hermits love food! A happy and healthy hermit crab will enjoy a wide variety of foods including fruits, vegetables, meat, fish, insects, grains and flowers. There are so many foods suitable for them it’s almost overwhelming. Make sure to always check that a food is safe before giving it to your crabs. Avoid any additives – including salt and sugars! Our shop: The Crab-Claw Café provides a wide range of dried food mixes safe and suitable for Hermit Crabs but remember to offer them fresh food as well. There is no such thing as a single staple diet and many crab pellet foods are actually very bad for them.

A hermit crab isn’t a hermit crab without a home. Aka shells! You must make sure that you have plenty of shells available for each crab. Without a good variety – your crabs may fight resulting in one crab being left either shell-less or in a shell that is not suitable. Please remember that natural is best. Avoid painted shells – they are toxic and extremely inhumane. Crabs sold in painted shells have often been forced out of a perfect, natural shell and shoved back in to a painted one. Look at a variety of turbo shells! They are beautiful and natural – often favoured by our crabby friends.

Finally – hands off! Hermit crabs are very much a look but don’t touch pet. They require the constant and stable heat and humidity to breathe. Each time you remove them from the perfect environment in order to handle them, you are causing them suffering and stress that will eventually lead to death. They can suffocate very slowly over time.

And now a thank you. We appreciate you taking the time to read through and consider the care of these amazing and complex creatures.

Ceonobita Rugosus emerging from a salt water pool.