Last Updated on October 1, 2023 by Joanne Harper
Hermit crabs are considered low-maintenance pets for children and beginners. However, they often struggle with life in captivity. To help hermit crabs survive as pets, they must be cared for properly.
Hermit crabs don’t cope well with solitude, so get 3+ hermit crabs.
Hermit crabs must live in a solid tank like an aquarium, not an open-air tank with bars. The tank’s temperature should be around 80°F, and the humidity level mustn’t drop below 80%.
The enclosure needs at least 6 inches of substrate, water to drink and bathe in, and lighting that offers the right dark-light balance. Also, items are needed for recreation so they don’t grow bored.
Feeding hermit crabs is easy, but they must be given enough calcium and protein.
Are Hermit Crabs Easy to Take Care Of?
Hermit crabs endure a reputation as delicate animals that die young, but that needn’t be the case. Well-cared-for hermit crabs can live for decades.
Keeping hermit crabs alive in captivity for the first few weeks of life will be the first challenge. If you clear this landmark, you can reap the rewards of caring for them.
How To Help Hermit Crabs Flourish as Pets
If you want hermit crabs to enjoy their life as pets and survive close to their potential lifespan, you’ll need to replicate their natural environment as best you can.
This comes under four core categories – providing company, offering an ideal habitat, feeding an appropriate diet, and offering entertainment and enrichment.
While the name ‘hermit crab’ suggests that they flourish when alone, the opposite is true.
Hermit crabs typically live in groups of 100 or more in the wild. Hermit crabs feel much happier and safer when living with conspecifics.
It’s unrealistic to expect you to get that many hermit crabs at once, but consider keeping a minimum of three hermit crabs together. The more company hermit crabs have of their kind, the less stressful they’ll find the adjustment to captive life.
It’s always advisable to tackle a hermit crab tank setup before introducing your new pets to their new home. If you can ensure that an aquarium matches the natural environment of hermit crabs, they’ll adjust much faster and are likelier to survive.
Hermit crabs’ earliest days of life in captivity tend to be touch-and-go. Some hermit crabs can’t cope with the stress of being plucked from a beach and forced into life as a pet, especially if they spend time in a beachfront shop living under inappropriate circumstances.
If you understand what hermit crabs need in their cages, you’ll have a better chance of keeping your pets alive long enough to flourish. So, let’s review the ideal setup for a permanent hermit crab habitat:
Size and Design
Hermit crabs can’t live in open-air cages like those typically provided for small rodents.
Terrestrial hermit crabs hail from tropical environments and breathe through gills, so they need to maintain humidity. Pick up a fish tank or reptile vivarium for your pets.
The ideal hermit crab tank size depends on how many hermit crabs you keep. The more hermit crabs dwell in a single habitat, the larger it must be to avoid conflict. Most hermit crabs are docile, but fights over territory happen.
A tank of 10 gallons will usually be OK for a small number of hermit crabs. If you’re taking on five or more hermit crabs, it’s better to get a 20-gallon tank. The wider and taller the tank, the more opportunities the hermit crabs will have for entertainment and environmental enrichment.
Having substrate at the bottom of a hermit crab tank is non-negotiable. Playground sand from a toy store is usually fine. If you use any other kind of sand, such as that purchased from a builder’s merchant, ensure it is devoid of debris and sanitize it thoroughly.
Hermit crabs need at least six inches of bedding in their habitat. If you have multiple hermit crabs, add a couple of inches more. Hermit crabs burrow under the sand to hide, sleep, and molt. They must have enough substrate to allow this behavior.
Hermit crabs are ectothermic (cold-blooded) and rely upon external heat sources to stay alive.
According to Animal Biology, prolonged exposure to inappropriate temperatures is fatal for hermit crabs, so provide a heat lamp.
80 OF is widely considered the optimum temperature for a hermit crab enclosure. You can drop the temperature but never allow a tank to become cooler than 72°F.
At this point, the hermit crabs within will grow stressed and unwell, eventually dying.
Humidity is as vital to hermit crabs as temperature, so hermit crabs must live in an enclosed habitat. The moisture in the air needs to be sealed within a tank.
Get a hygrometer for your hermit crab tank and keep humidity levels at around 80% – avoid letting it drop below 70%. Without sufficient humidity, a hermit crab’s gills close, so they slowly suffocate.
Keeping moss in a hermit crab tank is a great way to maintain humidity, as can a small water feature. If you need to increase the air moisture in a tank manually, use a misting spray.
Lamps in a hermit crab enclosure aren’t just for heat but also light. Your pets also need a varied light-and-dark schedule to regulate their circadian rhythms. Use LED or fluorescent bulbs to avoid the intensity of high-output UVB bulbs.
Hermit crabs need around 8–12 hours of light each day in their habitat, depending on the season. This mimics the sunlight hermit crabs encounter in the wild.
Your hermit crabs will likely remain burrowed under the substrate while the lights are on, just as they hide from intense, direct sunlight on the beach. When the lights begin to dim, these nocturnal animals will rise from the substrate and seek food.
Hermit crabs should have two water sources in their tank: one for drinking and another for bathing.
Never use tap water in a hermit crab enclosure, as this contains chlorine, which is toxic to hermit crabs. Offer a bowl of filtered or bottled water to drink.
Bathing water should contain a little saline solution to mimic the sensation of spending time in seawater.
Don’t use table salt – pick up a specialist solution from an exotic pet store. According to African Zoology, access to saline water helps hermit crabs tolerate sub-optimum temperatures better.
Don’t worry if you spot your crab sinking into the water, as this allows the water to sink into the hermit crab’s gills, making breathing easier.
Hermit crabs can drown if they spend too much time underwater, so rescue the hermit crab if it has been submerged in water for over 20 minutes.
Shells are crucial to hermit crabs, so always keep a selection of spares in a habitat.
You can forage for these on a beach, sanitizing the shells before adding them to the tank. Alternatively, you can purchase shells online from specialist traders.
Hermit crab shells must never be painted. Paint is toxic to hermit crabs and can result in the animals growing trapped within a shell. If you acquire a hermit crab with a painted shell, try to coerce it into a different shelter.
The opinion is divided among experts on whether pellets marketed as hermit crab food by exotic pet stores are necessary. As wild scavengers, hermit crabs are used to finding their meals.
Perhaps more importantly, scavenger status means hermit crabs like variety in their food.
Offering dry, bland pellets will cause boredom and distress. The Journal of Experimental Marine Biology and Ecology explained how hermit crabs crave different foods.
Hermit crabs are omnivores, so you can offer a rotating variety of fruits and vegetables, nuts, meats, and anything else you consider suitable. Hermit crabs aren’t fussy about freshness, so you can offer fruit and veg that’s starting to turn.
Don’t feed them anything rotten, as this will contain harmful bacteria. Focus on foods high in calcium and protein because these nutrients help hermit crabs grow and maintain their exoskeletons.
For additional calcium, you may want to consider supplements or a cuttlebone.
Toxic Foods for Hermit Crabs
Hermit crabs have strong stomachs, so few foods are considered toxic. Remember, they scavenge to survive and are used to consuming food considered rotten by human standards.
Garlic, onion, and citrus are best avoided, and any fruits or vegetables should be washed thoroughly to remove potential traces of pesticides or herbicides.
Look for ethoxyquin in any dry products, even if they’re marketed toward exotic pets. Ethoxyquin is a preservative that prevents meats from spoiling and is common in fish foods. Unfortunately, it’s toxic to hermit crabs.
Previously, hermit crabs had an entire beach to traverse and explore. Now, they’re limited to the confines of an aquarium, so provide toys and environmental enrichment.
If you’re short of ideas for keeping hermit crabs entertained, consider their three favorite activities – digging, hiding, and climbing. Providing sufficient substrate will encourage hermit crabs to dig for their amusement.
Hiding places for hermit crabs are also comparatively simple to source. Pick up some decorations for a fish aquarium, provided they aren’t painted. The flakes of the paint, or any fumes that emit from them, can prove toxic to hermit crabs.
If in doubt, sanitize and recycle plastic or driftwood, or use rocks that hermit crabs can hide behind. As with other materials, these rocks should be boiled or baked to remove fungi or bacteria.
Rocks double up as climbing toys for hermit crabs. These animals love this activity, so consider purchasing climbing apparatus from pet stores.
You’ll also find that hermit crabs love to climb the walls of an aquarium, possibly even hanging from the ceiling afterward. Provide enough substrate to cushion a fall and secure the tank’s roof.
Keeping hermit crabs alive – and more importantly, happy and thriving – isn’t as easy as you may have believed. If you take appropriate care, you can enjoy a long and enjoyable relationship with your pet hermit crabs.