Hermit crabs aren’t born with shells, so they must find an appropriate shelter through scavenging. Once a hermit crab has sourced a shell, it’ll protect it with great ferocity.
There may come times when you need to get a hermit crab to leave its shell. Perhaps the damaged shell is covered with toxic paint or unfit for purpose.
In such an instance, never force the hermit crab out of its shell.
If you try to pull a hermit crab out of its shell, it’ll likely pinch in self-defense or shed limbs in fright.
These will regrow during the next molt, but a stressed hermit crab may not live long enough to see that. Forcing a hermit crab out of its shell can expose it to dehydration and suffocation.
Hermit crabs will leave their shells voluntarily if they have a better alternative available, so make this process the hermit crab’s choice. With sturdier shells available, a hermit crab will likely vacate voluntarily.
Do Hermit Crabs Ever Leave Their Shell?
While shells are vital to a hermit crab’s survival, it’s just as important that they can leave their shells if necessary. Hermit crabs may choose to leave their shell for several reasons, including:
- Preparing to molt and anticipating an increase in size necessitates a bigger shell.
- Damage to a shell that leaves it no longer fit for purpose.
- Detection of a superior shell the hermit crab wishes to try on for size.
- Desire to submerge the skin entirely in saltwater for hydration.
- Awareness of impending death – as per Ecology and Evolution, conspecifics scent a dead hermit crab and approach to lay claim to its shell, so the incumbent may choose to make this process easier.
Overall, hermit crabs rarely voluntarily leave their shells. Doing so, and leaving the shell unguarded, is akin to you walking away from your house and leaving the door wide open.
Can You Remove a Hermit Crab from its Shell?
We’ve established that hermit crabs are unlikely to leave their shells by choice, but there may be occasions when you need to remove a hermit crab from its home. Examples include:
- You purchased a hermit crab from a beachfront gift shop, which is housed in a toxic painted shell that you are keen to change.
- The shell is visibly damaged, but the hermit crab seems reluctant to make a change.
- Other hermit crabs covet the shell, and its presence causes friction in a colony.
- The hermit crab has outgrown the shell and appears trapped within, unable to exit if it wanted to.
You can’t grab, yank, and hope for the best when getting a hermit crab out of its shell.
What Happens if You Pull a Hermit Crab Out of its Shell?
Attempting to forcibly pull a hermit crab out of its shell will result in unnecessary trauma.
Hermit crabs will defend their shells with life and limb. Any attempt to relocate a hermit crab against its will invariably results in the following outcomes:
Like all animals, hermit crabs respond to a threat with a fight-or-flight response.
If a hermit crab is frightened, it’ll likely retreat inside its shell and hide until a threat passes. However, some hermit crabs will stand their ground and fight.
Hermit crabs don’t have teeth, so they’re unable to bite. Hermit crabs defend themselves by pinching with the large cheliped. PLoS One explains that the coconut crab has a pinching force of up to 3,300 newtons, which is stronger than the bite of a wild dog.
Thankfully, coconut crabs are illegal as pets in the USA, and the pinch of the Caribbean or Ecuadoran hermit crab is much lighter. Alas, it can still sting and cause a shock, which may cause you to drop and injure your hermit crab.
Hermit crabs regenerate lost limbs when they molt, meaning they may shed limbs while wrestling for the right to remain in its shell.
To the hermit crab, losing a leg or two is the lesser of two evils compared to sacrificing a shell.
Just because hermit crabs can regrow limbs doesn’t mean it’s no big deal when they shed. It may be a year or longer before your hermit crab is next scheduled to molt.
It’s challenging for a hermit crab that sheds a large or small cheliped. Without claws, hermit crabs are less able to defend themselves. Perhaps more importantly, hermit crabs rely on claws to eat and dig.
Dehydration of the Skin
Shells shield hermit crabs from the heat and UV rays of the sun. If a hermit crab is forced out of its shell in a habitat, UV lamps or other heat sources may dehydrate the skin.
A hermit crab without a shell may struggle to maintain humidity. If the humidity level of a hermit crab drops below 80%, it becomes increasingly difficult to breathe through its small gills.
Exposing a hermit crab to such conditions for prolonged periods leads to skin dehydration. The humidity and protection afforded by the shell keep the gills damp.
If your hermit crab is exposed to too much dry air, it’ll suffocate.
Consider the stress that forced eviction inflicts upon hermit crabs.
You can forget any chance of the hermit crab trusting you again. It’ll likely remain near-constantly within its shell and potentially burrow under the substrate to seek safety.
Hermit crabs don’t cope well with intense stress, and the shock of being dragged from a shell may prove fatal. If the hermit crab remains in hiding for a month or longer, it’s unlikely to gain sufficient nourishment and hydration.
How To Safely Get A Hermit Crab Out of Its Shell
The process must be voluntary, but that doesn’t mean you can’t tempt and coax hermit crabs out of their shells. You need to avoid any traumatic encounters.
Try tempting a hermit crab with food. Like most animals, hermit crabs can be influenced by their stomachs, especially if you offer a sweet treat that provides a novel and unique scent.
Naturally, there’s a difference between hermit crabs poking their heads out of a shell and abandoning their shelter altogether. Here are some ways to achieve a safe shell evacuation:
You wouldn’t agree to move out of your home unless you had somewhere else to go. The same applies to hermit crabs. If you want a hermit crab to leave its shell, offer it an upgrade.
While hermit crabs grow attached to their shells, they always keep one eye open for something better. Place a selection of shells that may meet your hermit crabs’ needs in a habitat.
You’ll likely find that all your hermit crabs line up and start an exchange chain.
Providing a saltwater bath may loosen the grip and permit freedom if a hermit crab is trapped. Equally, this is a way to tempt a hermit crab out of its shell if you feel it needs to switch for safety reasons.
You’ll find the appropriate salt mix in exotic pet stores. Follow the instructions on the packaging and set up a deep enough bath for a hermit crab to submerge itself.
Allow your hermit crab to locate the bath or place it in the water. Eventually, a hermit crab will disappear under the water, which enables the water to sink into the skin and offers hydration.
Hermit crabs can’t hold their breath indefinitely, so supervise this process. Most can stay underwater for around 20–30 minutes, although juveniles rarely last longer than 10 minutes. Gently lift your hermit crab out of the bath for air if it has been submerged for too long.
Once your hermit crab is out of the bath, tempt it out of the shell by offering an alternative. If the hermit crab wants to trade but is stuck or interested in an upgrade, it will be much easier to liberate itself from the incumbent shell after bathing.
If you’re desperate to get a hermit crab out of its shell, increase the temperature until it’s so uncomfortable it feels like there’s no choice but to vacate. This should only be attempted as a last resort.
Place the hermit crab that stubbornly refuses to leave its shell in an isolation tank and steadily increase the ambient temperature.
Start at a comfortable 80OF, upping this by a degree or two every hour. Eventually, the hermit crab will grow so hot and uncomfortable that it seeks liberty from its shell.
Ensure replacement shells are available and return the temperature level to normal.
How to Remove a Dead Hermit Crab from a Shell
Captive hermit crabs have a comparatively short life expectancy due to sub-optimal care, although this can be increased by providing optimum living conditions.
If you fear that your hermit crab has died, ensure it’s not just molting. Hermit crabs undergoing a molt may be static and buried under the substrate for weeks or months.
The key signs that a hermit crab has died include:
- A putrid stench of rotting fish.
- Gathering of other hermit crabs. Conspecifics will be interested in a shell, and as per the Journal of Experimental Marine Biology and Ecology, they sometimes engage in cannibalism.
- No movement overnight for several days. Even a molting hermit crab may briefly emerge to eat or drink when the environment is quiet.
If you’re certain it has expired, you need to know how to get a dead hermit crab out of its shell. The easiest way to achieve this is:
- Place the hermit crab in a zip-loc bag.
- Freeze the bag for several hours to stiffen the body.
- Extract the hermit crab from the shell using tweezers and dispose of the body.
After this, you can sanitize and clean the shell and return it to the tank. The surviving hermit crabs will decide who, if anybody, should inherit it.
While hermit crabs aren’t born with shells, they protect these additions with all they have. This means that a hermit crab must never be forced out of a shell against its will.