Last Updated on: 20th October 2023, 02:39 pm
Hermit crabs hide in their shells when feeling vulnerable. A shell offers protection for their soft bodies. They hang onto their shells with hook-shaped tails until they feel safe.
Offering a choice of strong shells in the right sizes is the best way to get a hermit crab to leave its shell. Also, if you want to see a hermit crab, you may be able to lure it out with sweet-tasting food.
Don’t force a hermit crab to leave its shell against its will. Never attempt to pull a hermit crab out of its shell because it could lead to limb removal and cause stress. Also, you’re likely to get pinched.
Do Hermit Crabs Leave Their Shells?
Shells are crucial to the safety of hermit crabs, so they rarely leave them entirely.
If hermit crabs don’t have a shell on their back, they have no protection from predators. Moreover, hermit crab shells are precious commodities, meaning a rival will soon claim an unguarded shell.
Hermit crabs leave their shells to molt, trade up for a better shell, or cool off when it’s hot. They’ll also poke their head out of their shells to eat food, explore, climb, or due to curiosity.
Don’t worry if you seldom see pet hermit crabs leave their shells. As nocturnal animals, they often only surface after dark when humans are less active or asleep.
Why Would You Need a Hermit Crab to Leave its Shell?
Never drag a hermit crab from its shell to show friends or attempt handling because this will lead to needless stress. The situations below are reasons for luring hermit crabs out of their shells:
Happy and healthy hermit crabs should be active and curious when it gets dark. If you never see a hermit crab move, especially if it has stopped eating and drinking, it’s likely mentally or physically unwell.
Common signs of health problems in hermit crabs include:
- Dull, gray coloring, although this precedes molting.
- Inappetence, as hermit crabs won’t survive beyond 2 weeks without food.
- Lost limbs and eyes.
- Shell rot (black or dark green patches).
- Hanging out of the shell.
If a hermit crab is sick, isolate it from its tankmates to prevent contagion and aid recovery. If there’s a rotten smell, your pet hermit crab has likely died.
You may want to know the gender of a hermit crab out of curiosity, to choose a name, or because you have concerns about mating.
If it’s the latter, don’t worry because hermit crabs rarely breed in captivity, so you can safely keep males and females in the same enclosure.
You can tell if a hermit crab is male or female by its legs. The legs of males are hairy, while females have smoother legs. Once they emerge, it’s easy to tell them apart.
Look above the third pair of legs. If you see 2 small holes, called gonopores, it’s female. The sperm of the male is deposited into the gonopores during mating.
According to the Marine Biological Association of the United Kingdom, you may have an intersex hermit crab with gonopores and a penis. However, the gonopores close with time, so they’re males.
Wrong Shell Choice
Sometimes, a hermit crab will insist upon remaining in a shell that’s no longer fit for purpose. This may be a shell that’s too small and restricts mobility. Alternatively, the shell may be cracked or broken.
Encourage hermit crabs to leave shells that have outlived their usefulness.
How to Get a Hermit Crab to Change Shells
A better alternative must be offered if you want a hermit crab to change shells.
Temporarily separate the hermit crab from its tank mates. When one hermit crab changes shell, it sparks a trade among others.
The Annual Review of Sociology calls this a vacancy chain. Also, a dominant hermit crab will be the first to accept or reject a new shell.
Provide shells of varying shapes and sizes. Douse the shells in saltwater, as this makes them more appealing. According to Oecologia, hermit crabs prefer previously occupied shells.
Why Doesn’t My Hermit Crab Come Out?
What does it mean when a hermit crab won’t come out of its shell? Assuming that hermit crabs aren’t sleeping or molting, they’ll emerge eventually. If not, explanations include:
Stress and Anxiety
Some hermit crabs struggle with life in captivity, especially when you first bring them home. Post-purchase syndrome (PPS) is common in hermit crabs.
A distressed hermit crab should be left alone. Forcing them to interact against their will does more harm than good. The hermit crab will emerge when it feels ready.
Long-term residents of an enclosure can grow stressed. The explanation is more difficult to identify, so consider what unfolds inside the tank. Common reasons for stress include:
- Unsanitary living conditions.
- Bullying and aggression.
- Wrong humidity level.
Find out why your hermit crabs are stressed and make suitable adjustments.
Fear of Losing Shell
As explained, shells mean everything to hermit crabs, which can lead to them coveting shells worn by tankmates. Hermit crabs may attack each other to claim a prized shell.
Not all shell competition is aggressive. As per Proceedings of the Royal Society of London, sometimes it can take the form of shell rapping.
Shell rapping involves one hermit crab colliding with increasing force against the shell of another, which is a challenge for the shell.
It’ll emerge if the resident hermit crab wants to accept the challenge. Conflict will follow, although it rarely turns to outright aggression.
If the occupant doesn’t want to risk losing its shell, it’ll stay inside. The hermit crab may also vibrate to warn the challenger off.
Hermit crabs are reluctant to leave their shells because exposure risks shell loss.
Hermit crabs eat, mate, and defecate within their shells. Then, they flick any stored feces onto the substrate with their rearmost legs.
Unwanted Mating Attention
Females may refuse to leave their shells if they receive unwanted male attention. Males can detect when a female is fertile, so they respond by guarding the female and fighting off other males.
The male will gently rock the female’s shell back and forth. This is an invitation to mate.
If the female is interested, she’ll emerge. If not, she’ll remain inside the shell. She’ll stay inside the shell until the male grows bored and moves on, which can take several days.
Stuck in Shell
Hermit crabs sometimes insist on remaining in shells that no longer fit, which can become problematic. The more a hermit crab grows, the tighter the shell will become.
Eventually, the hermit crab may get stuck in the shell. Encourage the hermit crab to bathe in saltwater to loosen its grip. From there, entice it out with food.
Wet paint can trap hermit crabs in a shell, so avoiding painted shells is essential. Place the hermit crab in warm water to briefly bring water into the shell and turn the paint into a paste.
Take a paperclip and separate the hermit crab’s skin from the shell. Tempt the hermit crab out and throw the shell away so it isn’t reused. Then, offer several suitable unpainted alternatives.
How To Get A Shy Hermit Crab To Come Out
If hermit crabs resist leaving their shells, you must be patient, as there’s every chance hermit crabs will emerge after dark. If you need a faster response, use these techniques:
Hermit crabs are shy animals, but they’re governed by instinct. You can usually tempt hermit crabs out of their shells by promising rewards.
The promise of a new shell is usually compelling. However, this may also attract other hermit crabs, and nervous hermit crabs will stay away to avoid confrontation.
According to the journal Behavior, the scent of food encourages hermit crabs to get mobile.
Place a strong-smelling favored food within reach of the shell opening. Fruit is a favorite, as hermit crabs love sweet tastes and scents.
You’ll likely see the antenna twitch from outside the shell, which means the hermit crab is smelling the air. This will soon be followed by investigating the food.
Most hermit crabs leave their shells when handled, which can be a strange sensation. Hermit crabs poke their heads out of their shells to discover what’s happening.
This can be a good test regarding whether a hermit crab trusts you. It’ll emerge to smell your skin if you have a good relationship. If not, the hermit crab will chirp and retreat to its shell.
In the latter case, be cautious, as hermit crabs can still pinch from within their shell. If hermit crabs have reason to fear for their safety, they’ll use their claws.
Turn Up The Heat
If you feel too warm, you’ll likely remove a layer of clothing. Hermit crabs follow the same protocol, so it’s common for hermit crabs to leave their shell when it’s too hot.
This isn’t sustainable because hot hermit crabs will become uncomfortable and dehydrated. The reason hermit crabs are nocturnal is partially to avoid the heat of the sun.
Once the hermit crab leaves its shell, reduce the temperature. Most hermit crabs prefer a temperature of 80 degrees Fahrenheit, but anything above 72 degrees Fahrenheit is deemed safe.
Submersion in Water
Much like handling, water often brings hermit crabs out of their shell. Gently lift the hermit crab and place it in a body of saltwater with a ramp for easy exit.
Use this as a last resort. It usually works, but if it doesn’t, you place hermit crabs in jeopardy, as hermit crabs can drown. If hermit crabs hide due to fear or are stuck in their shell, they may remain within.
It’s believed that hermit crabs can remain submerged for 20 minutes but remove them after 10 minutes if they don’t emerge voluntarily.
Never force a hermit crab out of its shell, as they stay inside for personal reasons, unfathomable though they may be to us. A hermit crab will emerge when ready.