Hermit crabs will often leave their shell in order to molt. When they do this their soft inner body is exposed to air and heat and will die quickly without the protection of a shell.
If a hermit crab leaves its shell try boiling the shell in dechlorinated water before placing it back inside. Also make sure the new shell is large enough for your hermit crab.
Molting
If your hermit crab has left its shell, it may be in the pre-molting stage (also known as proecdysis). During this time, the crab will urinate into the empty shell to prepare itself for shedding. This is a natural process that can’t be controlled, but you can help the crab along by removing its old shell and offering several larger shells for it to choose from.
Molting is an energy-intensive process that requires a lot of calcium and protein. You can help the hermit crab by offering high-protein foods, such as dried shrimp or mealworms. This will encourage it to eat enough so that it can create a new exoskeleton and replace any lost appendages. It also helps to provide extra sources of calcium, such as crushed eggshells or cuttlebone, so that it can store up the reserves it will need for the upcoming molt.
When the hermit crab sheds its old shell, it can be very weak and will need some time to recover. This is when you will need to be most careful, since the crab is most vulnerable to predators and other environmental stressors. Keep an eye on the crab, make sure it has food and water available and provide a safe shelter, such as a tupperware container with the bottom portion of a two-liter bottle placed over the top for ventilation and a few suitable shells inside.
After the hermit crab has a few days to recover from molting, it can be returned to its habitat with its companions. It will need to be acclimatized slowly so that it can avoid being eaten or killed by its companions or from escaping into the open and getting lost.
It will also be important to clean the empty shells used for this purpose. It’s a good idea to disinfect them with a povidone-iodine solution or boil them, so that any bacteria present on the shell will be removed. You will also want to wash your hands thoroughly before handling the crab and any shells it uses so that you don’t get any germs on the soft abdomen or legs.
Shell Fighting
In the wild hermit crabs use a variety of shells to protect their soft bodies. They do not have the hard exoskeleton protection other crabs have, and therefore they feel the need to have something on their back that can protect them from other predators. Hermit crabs have evolved to use the shells of other aquatic animals to make a home for themselves. In the wild a hermit crab will “throw” its claw or leg if another hermit crab tries to pull it out of its shell. This is a responsive behavior to keep the hermit crab safe and is an effective defense mechanism.
Hermit crabs will sometimes abandon their shells and search for a better one that fits. They are more likely to do this when they need to go through the molting process, or it is time for a season change in the environment. When a hermit crab does leave its shell, it is likely that another hermit crab will take the shell. This can lead to a hermit crab without its shell for long periods of time, which can cause stress and could be fatal.
A hermit crab may also leave its shell if it feels irritated in it. Often this is caused by debris or sand rubbing against the hermit crab’s carapace. It can also be the result of a pest or fungus in the shell that is causing discomfort. Cleaning the shell with dechlorinated water or boiling it will help to remove the irritants.
It is important to have a wide variety of hermit crab shells in the tank. There are several different sizes and shapes to choose from. Having a few options will prevent hermit crabs from fighting each other over the shells they want. It will also reduce the chances of hermit crabs leaving their shells due to stress.
Interestingly enough, it is thought that hermit crabs with more drive to swap shells are less likely to fight over them. This may have to do with the fact that hermit crabs with more shell-changing drive are not as quick to judge whether or not a given shell is suitable. They are also slower to react to the presence of an opponent and tend to initiate a shell-fight more slowly than their low-drive counterparts.
Shell Swaps
Hermit crabs need to protect their soft abdomens from predators and other dangers. Since they do not possess the ability to make their own shells, these creatures rely on discarded snail shells for protection. As these animals grow and get bigger, they will abandon their old shells in favor of new ones that are larger. While shell evacuation does not necessarily mean that something is wrong with the hermit crab, it is a good idea to help them find new homes before their soft bodies are exposed to the elements and their health declines.
When a hermit crab encounters a potential new shell, it will size up the new home to see if it is the right fit. If it is not, the hermit crab will wait around until a bigger crab comes along and steals the shell. This is called a “vacancy chain.” In a vacancy chain, the hermit crabs swap their shells in order of largest to smallest. This allows each crab to move up to a bigger shell without having to fight off other crabs that want to take it.
Often, a hermit crab will remain without a shell for weeks or even months before it gets big enough to need to switch to a new one. This is why it is important to keep a variety of shells in the hermit crab cage. This will ensure that there is always a suitable shell for the hermit crab when it decides to upgrade.
If your hermit crab is reluctant to change to a new shell, you may need to try some gentle persuasion. You can do this by placing it in a quarantine tank and creating optimal conditions (humidity, temperature, quite dark) to reduce stress and help the hermit crab feel comfortable and safe. Alternatively, you can place the hermit crab in a new shell and let it settle into it on its own.
It is important that the new shell you provide is not painted or decorated. Hermit crabs may be allergic to the materials used in the decoration of the shell and it could cause a rash or even death. Also, the new shell should be properly disinfected. You can wash it in a solution of povidone-iodine or boil it to kill any bacteria or other substances that may be living inside.
Hermit Crab Behavior
Hermit crabs love their shells; they’re more than homes, they protect them from predators and other hermit crabs. When a hermit crab has an empty shell, it can become depressed and agitated; it also makes them vulnerable to other potential threats. This can lead to an attempt to molt, which can be dangerous for hermit crabs who haven’t completed the process yet.
Hermits are able to store water and nutrients in their exoskeleton, which allows them to survive while they’re buried during a molt. This buried state lasts for weeks, and the hermit crab will need to be sure to have a home that they can move into once they’re ready to shed again. In addition, the hermit crab might need a fresh shell to accommodate a new set of appendages, such as their gills and antennae.
The crab’s gills and antennae are essential for breathing, and the hermit crab needs to keep them in a healthy position. Crabs who aren’t in their shells have a hard time breathing, and they’re susceptible to infections from bacteria or fungus that can form inside their lungs. In addition, the hermit crab’s gills and antennae help them sense their environment, and they need a clean, fresh shell in which to move to maintain their health and vitality.
In the wild, hermit crabs have no other way to protect themselves from predators than by retreating into their shells when danger approaches. This is why hermit crabs are often seen fighting aggressively over a good shell. The crabs’ limbs are built in such a way that they can easily “throw” their claws or legs if another hermit tries to force them out of their shell.
This is why it’s important for hermit crab owners to have a variety of shells in a wide range of sizes and shapes available for their crabs. The hermit crab will decide if the shell is good for them, and it may take a few hours or a day or two to fully move into the shell. A hermit crab without its shell could be an indication that it’s preparing to molt or is stressed, which requires immediate intervention from the caretaker.