Life is stressful for captive hermit crabs, as they’ve been taken far from their wild habitat, kept in unfamiliar conditions, and thrust into life as pets.
Avoid putting new hermit crabs straight into a primary tank because this will cause them further stress and anxiety. Instead, put the hermit crabs into a smaller isolation tank to destress.
Provide limited substrate, food, and water and give them time to adjust. In the main tank, mimic the natural habitat of hermit crabs so that they feel at home.
Do Hermit Crabs Get Stressed?
Stress, also known as Post-Purchase Stress (PPS), is a fact of life for hermit crabs, especially when new to captivity. If you don’t take steps to protect hermit crabs from PPS, they won’t survive for long in captivity.
Think about the journey the hermit crab has had to your home. It will have started life roaming free on the beach with its friends because hermit crabs are social and live in large colonies.
It would then have been subjected to the following:
- Plucked from the beach by a gatherer and put in a bucket.
- Housed in a tank with inadequate humidity and a suboptimal temperature.
- Fed a diet that it has no control over.
- Forced into a painted shell to add aesthetic appeal.
- Left to await sale or shipped to a wholesaler.
When hermit crabs reach their final destination, they’re cold, hungry, and dehydrated. Some are on the way to ill health or death, so they must be allowed to destress and recover.
How To Tell If Your Hermit Crab is Stressed
The sooner you recognize stress in hermit crabs, the sooner you can rectify the situation. Common warning signs that hermit crabs are stressed include:
- Shedding of limbs. One lost leg is a warning, but losing multiple legs is very concerning.
- Hiding constantly, whether within the shell or buried under the substrate.
- Refusing to eat, drink, or bathe.
- Unprovoked aggression, whether toward tankmates or owners.
- Climbing tank walls as if attempting to escape.
When you bring hermit crabs home, you must provide a well-optimized living environment.
Can Hermit Crabs Die from Stress?
Stress can kill hermit crabs. While they don’t endure heart failure due to stress, prolonged unhappiness causes other issues, which is why pet hermit crabs die within days or weeks of purchase.
Dehydration is common among stressed hermit crabs. A constantly burrowed hermit crab risks growing dehydrated, and there’s no way to know how dehydrated it was before reaching your home.
Stressed-out hermit crabs may starve to death. Given that this could take up to 2 weeks, it’s an unpleasant way to go. Hermit crabs coping with severe stress struggle surfacing to feed.
This may also be a matter of inability to eat, not unwillingness. As discussed, stressed hermit crabs shed their legs and may be physically incapable of accessing food.
Hermit crabs experiencing stress have lower immunity than happy and contented conspecifics. Weakened immunity is dangerous because there are hazards for hermit crabs in captivity.
Stressed-out hermit crabs are less likely to defend themselves from tankmates. If a dominant hermit crab attempts to take a shell, the submissive one may wearily accept this fete.
How To Help A Stressed Hermit Crab
The easiest way to assist a stressed hermit crab is to leave it alone. Most hermit crabs that are new to captivity will initially burrow., which lasts a few weeks, but they’re adjusting and want to be alone.
Before moving hermit crabs into their primary enclosure, set up an isolation tank.
Ensure the isolation tank has sufficient humidity and is warm enough. Ordinarily, 80% humidity and a temperature of 80 degrees Fahrenheit are recommended.
Steadily increase the humidity by adding moss to the tank. You can add humidity to the substrate, which should be lower than usual. If you give hermit crabs enough substrate to burrow under, they’ll do so.
Place just enough substrate to help the hermit crabs feel at home. Add small, shallow water pools for bathing, as new hermit crabs may have parasites.
Over several weeks, gradually adjust the environment of the isolation tank.
Increase the humidity, temperature, and amount of substrate. Add deeper bathing pools to replicate the conditions of the primary aquarium in the isolation tank. Eventually, you’ll be ready to move the hermit crabs into the main aquarium.
If you already have hermit crabs in the tank, they’ll help the new arrivals settle. Return the new hermit crabs to the isolation tank if there’s any bullying.
Why Is My Hermit Crab Stressed?
We have discussed the many reasons why hermit crabs can suffer from PPS. It’s not only new hermit crabs that experience stress, as resident hermit crabs can fall victim to stress and anxiety.
Hermit crabs require constant vigilance to ensure that they remain happy and healthy. Despite what you may have heard, certain dangers are never far away for hermit crabs.
Let’s look at why captive hermit crabs are likely to encounter stress. Refer to our list of symptoms; if you spot these in hermit crabs, you must identify and resolve the cause.
Inappropriate Living Conditions
As suggested, the habitat of pet hermit crabs should mirror that of outdoor living conditions. Failure to do so will remind them of their captivity, which isn’t natural for hermit crabs.
This doesn’t mean that all captive hermit crabs will be miserable by default. Create the correct living arrangement, so your hermit crabs will be as happy as they were in the wild; they’ll enjoy all the benefits without environmental threats, such as predators.
That said, it’s not always easy to maintain a perfect environment, so you’ll need to observe your hermit crabs’ behavior. At the first sign of disgruntlement, consider what’s causing unhappiness, as this will benefit everyone in the longer term.
Humidity and Temperature
The most important elements of a hermit crab habitat are humidity and temperature, which must mimic their natural environment. An easy way to remember this is the 80/80 rule.
Get a hygrometer to measure humidity in a hermit crab enclosure. The humidity level should be 70-80%, as it creates a moist environment that helps hermit crabs breathe. Hermit crab gills dry out in a habitat with insufficient humidity, so they’ll slowly suffocate.
If your humidity drops below 80%, use a misting spray. Also, consider adding moss to the substrate. If your hermit crabs like dirt, consider using creature soil as your primary substrate, as this contains moss.
Try to achieve a temperature of 80 degrees Fahrenheit in a hermit crab enclosure. This is the upper-temperature range, but most hermit crabs enjoy living this way.
If your hermit crabs appear stressed, reduce this temperature in small increments. Never drop the temperature below 72 degrees Fahrenheit.
Lack of Space
Conventional wisdom dictates that hermit crabs can live in a 10-gallon aquarium. The more pets you bring into a habitat, the more space they need. So, provide five gallons of space for each hermit crab.
While hermit crabs sleep together, they still like to explore their surroundings. Hermit crabs are territorial, so the more space they have, the less likely they’ll grow distressed and squabble.
Food and Water
Terrestrial hermit crabs can’t live underwater, as they can only hold their breath for so long.
Prolonged exposure to water will cause the hermit crabs to drown. Despite this, land hermit crabs submerge in water at least once daily, which wets the gills and aids breathing.
Submersion is like a bath for hermit crabs. As hermit crabs poop in their shells, daily bathing is essential. Provide two pools for hermit crabs, with ramps or climbing apparatus to aid entry and exit. One pool should contain saltwater and the other freshwater.
Don’t use table salt for the former, as hermit crabs are poisoned by iodine. Pick up marine salt from an exotic pet store. Never use tap water for the freshwater pool, as this contains chlorine and heavy metals that are toxic to hermit crabs. Use bottled water or get a water filter.
In addition to water, consider what you feed your hermit crabs. As natural scavengers, hermit crabs enjoy a varied diet, so avoid feeding the same food twice in 24 hours.
Even calm hermit crabs need hiding places, such as under the substrate or behind rocks. Despite being socially active, all hermit crabs need time to themselves on occasion.
Ensure the substrate in a hermit crab’s enclosure is deep enough to burrow. Six inches will usually suffice. You’ll likely find that your hermit crabs bury themselves to sleep or molt.
Smaller hiding places are also important. Even if this is just a plastic bottle, it provides privacy. Keep caps on these bottles, as you don’t want hermit crabs to mistake them for a shell and get stuck inside.
Hermit crabs are fussy about cleanliness in their habitat, as mold, fungi, or bacteria growth can harm hermit crabs’ health.
Hermit crabs dislike squalor, so they bathe regularly to keep clean and eat anything that clutters their enclosure. So, you’ll need to clean a hermit crab habitat regularly.
Perform daily spot cleaning to remove any droppings in the aquarium. Also, wipe down the walls and carry out a deep clean that renovates the habitat every three months.
Boredom and Loneliness
We have mentioned that hermit crabs are social and enjoy living in groups. As explained by Acta Ethologica, solitary hermit crabs experience higher stress and anxiety levels.
In addition to having company, hermit crabs need stimulation in their habitat as bored hermit crabs grow stressed. Climbing apparatus is a must, as hermit crabs are natural climbers. Providing netting and rocks to clamber over keeps hermit crabs amused for hours.
Lack of Shells
Shells are critical to the happiness and security of hermit crabs. A hermit crab with no shell will be experiencing significant mental distress, so always keep a range of shells available.
When choosing spares, select shells that match those your hermit crabs occupy.
Avoid painted shells because paints are toxic. If the paint chips, the toxins can make hermit crabs sick. Wet paint can also cause hermit crabs to get stuck in their shell.
When you provide new shells, you’ll notice that your hermit crabs line up to try them. In the wild, a dominant hermit crab will get the choice of a new shell.
Once accepted or rejected, the remaining hermit crabs will trade shells.
Excessive or Inappropriate Handling
Most hermit crabs prefer to avoid human interaction, as they’re unsure of your intentions. However, most hermit crabs can learn to tolerate handling.
Teach your hermit crabs that handling isn’t a bad thing. Once your hermit crabs have destressed to an extent, handle them one at a time. The best way to coach handling is to:
- Wear gloves to protect yourself from possible pinches.
- Stretch the palm of your non-dominant hand so that no loose skin is available.
- Grip the hermit crab by the shell (never the legs) with your other hand.
- Place the hermit crab in your palm, but don’t leave it midair.
- Offer the hermit crab a small treat.
- Return the hermit crab to its habitat.
Sometimes you’ll have no option but to handle hermit crabs, as they’ll need to be rehomed to molt, destress, or during the cleaning of an aquarium.
Disturbed when Molting
Young hermit crabs, especially males, molt several times a year. Molting occurs when hermit crabs grow too large for their exoskeleton. The hermit crabs shed entirely and grow a new exoskeleton, usually when burrowed under the substrate.
Molting hermit crabs must be left alone during this process. As the hermit crab has no exoskeleton, it has no protection, which makes it feel anxious.
Don’t worry about food and water, as hermit crabs eat more ahead of molting to store fat, which may resemble a fat bubble on the exoskeleton. Molting hermit crabs eat their shed exoskeletons and store water in their shell for this eventuality.
If possible, move your hermit crab to the isolation tank while it molts. During molting, hermit crabs appreciate being kept alone. With no rival hermit crabs around, it can molt in peace.
Bullying and Aggression
Hermit crabs are mostly docile and friendly to each other. As mentioned, hermit crabs are more likely to be stressed alone than in company. Just be aware of mismatched power dynamics between hermit crabs.
All hermit crab colonies have a dominant and submissive hierarchy, which is usually respected by all. However, sometimes a larger hermit crab will attack a smaller hermit crab.
Watch your hermit crabs interact. Check for a reaction if many hermit crabs surround one tankmate, knocking against its shell. If the hermit crab hides in its shell, it’s being bullied. Equally, if any hermit crab tries to pull another out of its shell, you should intervene.
Place the bullied hermit crab in the isolation tank to keep it safe. It’ll still need some company, so try different tankmates until you find the optimal combination.
Hermit crabs remember social dynamics, so reuniting them with a bully will cause further stress.
Hermit crabs can experience sickness, which could be due to toxins in the habitat. Common reasons for hermit crabs to grow unwell include:
- Fumes around the habitat, such as air fresheners or deodorants.
- Toxins in paint chips from painted cells.
- Bacteria and mold on walls and decorations.
- Copper and chlorine from tap water.
Hermit crabs rarely experience sickness from food. As per The Biological Bulletin, hermit crabs also learn quickly about harmful food consumption, avoiding these foods in the future.
The two main causes of injury are conflict with other hermit crabs or falling from a height.
Hermit crabs rarely aim to hurt each other in conflict, but accidents occur. Equally, some hermit crabs are more hostile than others. A well-timed use of pincers may injure a leg, eye, or abdomen.
Falling is also a hazard for hermit crabs. As mentioned, hermit crabs love to climb. If the hermit crab loses grip, it can take a tumble. Some hermit crabs get stuck on their back, dazed by their descent.
Ensure that your enclosure has sufficient substrate to offer a soft landing. If handling your hermit crabs, or letting them roam, monitor them carefully. A hermit crab can run off a hand or the end of a table.
Unfortunately, mites are the bane of hermit crabs, attracted to humidity and food. Then, they lay eggs, and their numbers become overwhelming.
Mites attach themselves to hermit crabs, usually the legs, eyes, and abdomen.
Hermit crabs will attempt to rid themselves of infestation by bathing in saltwater. If this is ineffective, hermit crabs may willingly amputate their legs.
The only way to deal with a mite infestation is to sterilize the enclosure. Relocate the hermit crabs temporarily and clean everything – walls, floors, toys, substrate, and decorations.