A Guide to Hermit Crab Care
Hermit crab care - for happy crabbies!
Beady little eyes, tiny little pinchers and a cute little shell...yep, we're talking about the hermit crab, a marvellously complex creature that makes a wonderful, rewarding pet with the correct care. And while that last part might seem like a given, many people aren't aware of how sensitive these little guys are: from the correct substrate to suitably treated water and specific heating parameters, hermit crabs need some extra special care to live a long, fruitful life. It doesn’t really do to dump a hermit crab in a tank with some sand and food bowls and call it a day - in fact, many of the plastic homes you see sold at pet stores include "ventilation" hoods that are actually causing the crabs to slowly suffocate. Eep! With that in mind, hermit crabs can be more difficult to look after than many reptiles.
But it's not all doom and gloom: a good understanding of what hermit crabs need before starting on your journey to owning a few will do you a world of good. Have a read of our care guide below, and maybe learn a hermit crab fact or two along the way.
Some things to consider before we begin...
- Hermit crabs do not make appropriate first pets for kids, unless you have an older child who understands their needs. Click here to check out our whole article on choosing the right pet for your child instead!
- A majority of land hermit crabs are caught in the wild, as captive breeding is very difficult. Make sure you are aware of this before purchasing a hermit crab, and consider adopting rather than buying
- Hermies love to be part of a big group, so don't just get one! They'll be much happier living in a community
- Hermit crabs can live up to thirty years! So make sure you can commit time and love to these long-lived critters
Early steps: set up the environment before you get your crabs
For all-out excellence when it comes to setting up your crabs' habitat, it's best to set up their tank well before you get your crabs arrive home. Monitoring the humidity and perfecting all the fine details of your crabs' future habitat will ensure that they are comfortable from the moment you place them in their tank. Here's a basic shopping list with things you need for your hermit crab:
- A glass aquarium tank (preferred), between 37 litres and 75 litres. Make sure it doesn't allow for your crabs to climb out while still allowing in a bit of air and keeping in humidity
- Hermit crab-friendly substrate. Some of the safest are play sand, all-purpose sand, or fibres made from coconut - all of which support burrowing
- Water conditioner for both fresh/drinking and salt water
- Sea salt (for creating your own salt water)
- A bowl each for fresh water, salt water, and food
- Sea sponges for humidity control, as well as a means of exit from food and water bowls
- Additional shells for growing crabs
- A hygrometer (for humidity) and a thermometer (for heat and sand) - ZooMed make a dual-purpose meter for these
- A heat source, such as a lamp (with a low-wattage bulb) or an under-tank heater
- Decorations and accessories, such as fake plants, upside down pots, branches, driftwood, rocks and places to hide
- Food! Currently we stock Blue Planet hermit crab food, as well as Hikari hermit crab food
Next steps: a bit more on food and water...
Your hermit crab's diet is central to their health, and has a few important aspects to take into consideration.
In the wild, hermit crabs partake in what's known as beachcombing - that is, they crawl down the beach and nibble on whatever they can find, whether it's a form of meat or a plant. This means that they are omnivorous - not to mention, picky. No one likes eating the same food again and again, and this goes for your crabbies as well! You can feel free to rotate fresh food with their store-bought food - we recommend meat such as fish and chicken, plus fruit and vegetables that have been washed with non-chlorinated water (this is very important!). Other delicious ideas include baby food, bloodworms and even low-salt cat food.
Another big part of your hermit crabs' diet is calcium - they need it in order to generate their exoskeleton. It's easy to include this essential in their daily life though: just drop a couple of cuttlebones in the bottom of their tank and let them nibble away.
Lastly, your crabs will need both fresh and salt water in their environment. You cannot use table salt in order to create their salt water either, as the iodine in table salt is harmful to your crabs. Opt instead for a hermit crab sea salt to create the right conditions. Fresh water should also be conditioned before being added to your crabs' tank. Make sure the bowls in which you offer your crabs' water is deep enough for them to submerge themselves, but not so deep that they end up drowning! You can pop a sea sponge in each bowl to act as a safety raft if you're worried.
Shells and shedding: important stages of life
Hermit crabs are famous for shifting from shell to shell as they grow, which is how they get their name. Understandably, these shells are very important to them, so you should be careful about what shells you supply your hermit crabs with. Often you'll see brightly painted shells in pet stores that act as jazzy new homes for your hermit crabs; we strongly advise against these, as they are often painted with toxic paint that your crab may ingest and will ultimately be harmful to their health. Instead, choose natural shells and aim to have at least three per hermit crab in your tank, such as these shells from Zoo Med, in three sizes: smaller than the current shell, roughly the same as the current, and larger than the current shell.
Aside from switching shells, hermit crabs will also undergo periodic moulting or shedding. This is why appropriate substrate (as well as substrate depth - at least 6 inches or 15cm) in your crabs' tank is important: it allows for them to dig down and prepare for shedding, where they use the darkness to secrete a moulting hormone to assist with the moult. Failure to provide the right environment for shedding will result in what's known as a surface shed. Young or small hermit crabs may survive this, but it’s less likely for a large or jumbo hermit crab.
Signs that your hermit is about to undergo a moult are:
- Increased digging activity
- Excessive time spent in salt and fresh water dishes
- Changing in to a smaller shell (this is because hermit crabs prefer to grow into a larger shell, and once they drop an old exoskeleton they will be a bit smaller than beforehand)
- Decline in activity level
- General change in look including dull eyes and exoskeleton
Moulting time can be confusing and stressful for new hermit crab owners - those not familiar with the action may think that their crab has buried itself and died, or that its shed exoskeleton is a dead crab. If you are unsure, the general rule of thumb is to assume that your crab is moulting before disturbing it or investigating further - it can take up to four weeks for your crab to complete a full shed, after all. You can try the following to determine whether or not your crab has expired:
- Check the tank for a rotten, fishy smell
- Gently touch an immobile, shell-less crab to see whether it reacts
- Smooth out the sand around a buried crab and examine whether it has moved to retrieve food overnight
A few takeaway notes
Hermit crabs are adorable and unique, as well as very active. They will keep themselves fit by crawling, climbing, and digging and pulling, so make sure they have lots of fun accessories in their tank! It's also worth mentioning that they'll do most of this at night-time, so we don't recommend having your hermit crabs’ tank in your bedroom - unless you want to get woken up by a midnight crab shindig.
Always monitor the heat and humidity in your crabs' enclosure; provide interesting new foods, climbing and hideaway décor; keep those water dishes safe, and you'll have some very happy crabbies indeed.
In her life, Gemma has owned cats, dogs, budgies, tropical fish, hermit crabs, chickens, guinea pigs, a rabbit and a stubborn rat named Bijou. She now writes all about pet wellbeing and products here at Pet Circle.
Gemma suggests to read:
A beginner's guide to setting up a fish tank ▶
Reptile Care 101 ▶
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