Hermit crabs prefer to keep all ten legs on a solid surface unless climbing. There will be occasions when a hermit crab willingly lies on its back, but this will only ever be temporary. If your hermit crab seems trapped upside down, help it right itself.
By its behavior, you can usually tell if a hermit crab is stuck upside down. If the hermit crab is still and quiet, it’s likely contented. If the legs are wriggling and the hermit crab is chirping, it’s growing distressed and needs assistance to get back on its feet.
Some hermit crabs choose to lie on their back to molt or sleep. Disputes can see one hermit crab flipped on its back by a rival. Hermit crabs can also get their shells trapped between obstacles or find themselves dazed after falling from a wall or ceiling.
Many hermit crabs like to hang upside down from the ceiling of a habitat. This doesn’t necessarily mean they’re stuck, especially during daylight hours. It’s likely your hermit crabs are sleeping in this position. However, check your pets are not trying to escape.
Why is My Hermit Crab Lying Upside Down?
You’ll typically be used to seeing your hermit crabs with all four legs on the ground or scaling the walls of a habitat. This can mean that it’s a little disturbing to find a hermit crab trapped on its back. Be aware this may be a conscious choice.
While hermit crabs usually prefer to sleep under their substrate, some will flip on their back on the surface and doze. If you notice this, consider adding more substrate to a tank. Your hermit crab may feel that it lacks enough space under the sand or soil to sleep well.
Equally, some hermit crabs habitually lie on the back, especially if purchased from a beachfront gift shop. Many vendors place hermit crabs in this position as they feel it makes them look more enticing to customers, and Hermit crabs get used to such a posture.
If your hermit crab is on its back by choice, it should only ever be a temporary arrangement. Offer food to a hermit crab and check how it responds. Most hermit crabs will immediately show interest and right themselves if possible.
If the hermit crab wriggles its legs and antennae but doesn’t flip over, especially accompanied by increased chirping, there’s a good chance it is trapped on its back.
Can Hermit Crabs Get Trapped on Their Back?
Hermit crabs can get trapped upside down. There are five commonplace explanations for this.
Flipped Over by a Conspecific
Hermit crabs playfight for recreation, which will take the form of feeler fights (also referred to as antennae wrestling) or strength tests. In the latter case, the two hermit crabs will take turns attempting to push each other over.
While playfighting is often enjoyed in the name of fun, it can also carry other meanings. As per Animal Behavior, hermit crabs abide by a social hierarchy, with one colony member enjoying alpha status. The test of strength may be engineered to bestow this honorific.
If two hermit crabs are playing, one flipped onto its back will be helped up by its friend. If the two hermit crabs are battling for dominance, the victor will leave its rival trapped on its back as a reminder of who is the foremost member of the group.
Some hermit crabs lie on their back and bury their shell under the substrate to avoid conflict with rivals in a habitat. This is especially likely if the hermit crab doesn’t want to accept a challenge from a tankmate for its shell.
As explained by Proceedings of the Royal Society of London, hermit crabs issue challenges for shells by rapping on the vessel. The incumbent hermit crab can emerge, accept, or hide within the shell and ignore the request.
Depending on how insistent the challenger is, the owner of the shell may grow anxious at this constant rapping. The aggressor can no longer make contact with the shell by flipping on its back, and this position also makes it harder to force drag a hermit crab from its shell.
Unfortunately, this position can also leave a hermit crab trapped. The conspecific that saw its challenge fail will be in no mood to help the stuck crab upright, so it may remain trapped in this position until help arrives.
Trapped Between Obstacles
Hermit crabs love to explore a habitat that contains rocks and other obstacles. Rocks make great places to climb and hide.
If a hermit crab slips and falls between two rocks roughly the same distance as a shell, it may become trapped and be unable to move until one or both obstacles are shifted.
Other hermit crabs may try to help in this instance, lifting the stuck hermit crab and allowing itself to right itself. If one hermit crab is stuck, others may stay away as they fear the same outcome.
Dazed from a Fall
The Journal of Crustacean Biology confirms that hermit crabs are natural climbers. You’ll see this for yourself, as most hermit crabs spend hours scaling the walls of the habitat for their amusement.
This is harmless fun for hermit crabs and a way for your pets to indulge their instincts. Climbing is exhausting, so some hermit crabs will grow tired – even fall asleep – and slip mid-ascent. If they fall from a height, hermit crabs can become dazed.
If you notice a hermit crab slip and fall, approach with caution. If the hermit crab is stunned, it won’t be thinking clearly and may become belligerent. The hermit crab may also want to catch its breath before attempting to right itself.
After a minute or two, work with the hermit crab to get it back on its feet. Check the shell for damage, and ensure the hermit crab is walking normally and has not broken any legs.
We have established that hermit crabs sometimes sleep on their back, but do hermit crabs molt upside down? It can happen, but you likely won’t see this, as hermit crabs prefer to molt in privacy buried deep under the substrate.
If your hermit crab is on its back in public and showing signs of molting, relocate it to a private habitat. While we ordinarily never condone moving a molting hermit crab, this is the lesser of two evils compared to leaving it exposed at such a vulnerable time.
Can Hermit Crabs Right Themselves?
While hermit crabs can right themselves, they usually can’t do so alone. Most hermit crabs will lack the strength to flip over while wearing a shell, so they seek leverage to make the process earlier.
If you keep rocks in a hermit crab enclosure, they serve as more than just décor. Rocks create helpful leverage for hermit crabs to pull themselves up when they fall over. Strategically place these decorations around a habitat.
You’ll likely need to get involved if your hermit crab doesn’t have anything nearby to pull itself up with. Put on a pair of gloves to protect yourself from any pinching, and prepare to assist.
Righting an Upside-Down Hermit Crab
Before you flip an upside-down hermit crab over, ensure it’s not on its back by choice.
If your hermit crab wishes to adopt this position, it’ll flip straight back and may pinch you for trying to change its posture against its will.
Follow these steps if you wish to turn over a hermit crab trapped on its back:
- Look for anything that may be pinning the hermit crab on its back, and remove these obstacles.
- Slide something flat, like a piece of card, under the substrate directly beneath the hermit crab.
- Lift the hermit crab on this surface just above the substrate – not too high in case the hermit crab slips off the side.
- Delicately lift the hermit crab from the back of the shell and rotate it to an upright position.
- Place the hermit crab back on the ground in the habitat.
At this stage, you should see the hermit crab move. Even if the hermit crab doesn’t emerge from its shell, you’ll likely see the antennae twitch. Take a step back and remove your hands from the tank at this point.
Why is My Hermit Crab Hanging Upside Down?
If you wonder, “do hermit crabs sleep upside down?” the answer is an unqualified yes. Some hermit crabs like to hang from the tank ceiling while dozing during the daylight hours, akin to roosting bats.
Don’t try to break this habit if it makes hermit crabs happy. Ensure you provide enough substrate to soften the impact if they fall on their back. Six inches will usually be sufficient.
One other thing to consider if hermit crabs seem to hang upside down for prolonged periods is whether they are plotting an escape attempt. Many hermit crabs struggle with life in captivity and may be seeking a structural weakness in the habitat.
Watch the general demeanor of your hermit crabs. If they seem stressed or bored, spending more time hiding than interacting, they’re unhappy with their living arrangements.
It’s also possible that your hermit crabs have grown trapped within the ceiling. If the legs and feet of the hermit crab are wrapped around the roof, it may find it impossible to get free. In these instances, hermit crabs will chirp in distress.
You’ll need to help release your hermit crab without risking damage to its legs. If the hermit crab thinks you mean it harm, it may willingly shed a leg and plummet to the ground.
Hermit crabs can get stuck upside down. If that is the case, they’ll sometimes need your assistance.