Wild hermit crabs eat and drink infrequently. As per Estuarine, Coastal, and Shelf Science, wild hermit crabs spend their days burrowed under the sand, enabling them to avoid the sun and stay away from predators.
Hermit crabs may refuse to eat or drink due to stress, being fed the same foods, a lack of saltwater (muting their sense of smell), excessive noise, and disturbances. Hermit crabs can go for 3-14 days without eating food and drinking water. They store water in their shells so that they can moisten their gills.
In theory, your hermit crabs can survive for up to 2 weeks without eating or drinking. However, happy and healthy hermit crabs will never intentionally deny themselves food or water.
Do Hermit Crabs Eat and Drink Every Day?
When the sun goes down and the temperature cools, hermit crabs will emerge from hiding. This is the time they seek food and water. They will traverse a beach, seeking nourishment and hydration. Upon eating their fill, hermit crabs return to the safety of their burrow.
Pet hermit crabs begin life in the wild as breeding in captivity is practically unheard of in hermit crabs. This means that they will be accustomed to eating daily, so you need to replicate this in captivity.
How Long Can Hermit Crabs Live Without Food or Water?
Hermit crabs can survive for up to two weeks without eating or drinking. However, survival is different from thriving.
Many people assume that hermit crabs can survive for a long time without nourishment as they burrow for weeks at a time while molting. This is not entirely accurate. While hermit crabs may stay under the substrate during a molt, they do not deprive themselves of food or water.
Hermit crabs understand when a molt is impending. They will take this opportunity to eat and drink more than usual. This helps them to add additional fat onto their exoskeleton and store water in their shells.
While molting, hermit crabs sustain themselves on their shed exoskeleton. As noted, this will contain more fat than usual. This will keep them nourished throughout the process. Likewise, water stored in the shell provides hydration until they eventually resurface.
What Happens When Hermit Crabs Stop Eating or Drinking?
If deprived of food and water for too long, hermit crabs will grow sick and die. Refusing to drink is the most concerning of these behaviors. Even land hermit crabs need regular exposure to water. They live in hot, tropical climates, so your aquarium should be heated to 80 degrees. This means that hermit crabs must hydrate to remain alive.
As well as quenching thirst, drinking water keeps the gills moist. If these gills dry out, breathing becomes increasingly difficult. This will eventually lead to your hermit crabs suffocating.
Hermit crabs don’t just use food for energy; they also need protein and calcium to maintain a strong, healthy exoskeleton. These nutrients are gained from food. If your hermit crabs are not eating, they will grow increasingly frail.
My Hermit Crab Won’t Eat
Hermit crabs refusing to eat is not an everyday occurrence. While they are not glutinous animals, this doesn’t mean that they will starve themselves.
Some hermit crabs are pedantic about when they eat. If you serve dinner at sundown, not all of them will immediately eat. Some prefer to dine later in comparative privacy.
As hermit crabs are nocturnal animals, they may be eating after dark. If you leave food overnight and it has disappeared by morning, this will be the explanation.
As hermit crabs are natural scavengers, they may be hiding their food. Instinct is a tough habit to break, after all. Try not to let this continue as buried food may be forgotten. This leads to it spoiling and becoming a bacterial hazard.
Hermit crabs eat every day, but they eat in small quantities. If you place large amounts of food in an enclosure, there may be a lot left. This can give the impression that the hermit crabs are starving themselves.
The hermit crabs may have eaten their fill. Don’t forget that the food you serve in a dish is not the only thing that hermit crabs eat. They may also have eaten any insects in their enclosure, as well as wood, moss, and algae.
Offer your hermit crabs some honey from the top of your finger. Even when full, most hermit crabs find this irresistible.
Negative Connotations with Food
Hermit crabs can forge an emotional connection with food. They certainly know what they like. More importantly, they will always remember a negative experience. As per The Biological Bulletin, hermit crabs will avoid food that previously made them unwell.
For example, hermit crabs may show a sudden and unexpected aversion to fresh fruit. This may be down to fussiness. Alternatively, your hermit crabs may have buried fruit until it went rotten.
If the hermit crabs ate this spoilt fruit and experienced negative physical side effects, it will not be forgotten. They will retain a memory of how the food made them feel. As a result, they have no intention of experiencing such physical distress again.
As explained by Behavioral Processes, the scent of food alone can be enough to deter hermit crabs from eating. This is why it is important to manage food exposure. If hermit crabs consider all food smells to be negative, they may cease eating completely.
Excessive External Stimulation
If your hermit crabs have stopped eating for seemingly no reason, consider if anything has changed outside their habitat. External stimulation can be distressing and distracting to hermit crabs.
As per Animal Behavior, hermit crabs find their senses dulled by ambient noise. While it’s unlikely that passing ships will disturb the meal of hermit crabs, other external sounds could do so.
If you’ve moved the aquarium, this could explain their reluctance to eat. They are now picking up on external sounds, such as music or TV. If you provide quieter surroundings, the situation may improve.
Lack of Saltwater
Hermit crabs need two disparate water sources in their habitat. One of these should contain freshwater and the other saltwater. The latter is critical when it comes to feeding, as is appropriate humidity. Without these elements, hermit crabs cannot smell food.
Proceedings of the Royal Society explains how hermit crabs rely on water vapor to activate their sense of smell. If they scent something tasty, their antennae will start to twitch. They will investigate the food source and, under ordinary circumstances, eat.
If the habitat has a humidity below 80% or no marine salt in the water bowl, these senses are blocked. Hermit crabs will never eat what they cannot smell. Rectifying these issues may stimulate a hermit crab’s appetite.
Almost all hermit crabs go through an experience known as post-purchase syndrome (PPS). This is a period of intense stress upon transitioning from the beach to an aquarium.
Hermit crabs remain burrowed under the substrate throughout PPS. This is known as de-stressing. You mustn’t disturb your hermit crabs at this point. They will emerge when they are ready and will hopefully start to eat.
Be aware that stressed hermit crabs may shed limbs. This could include their claws (chelipeds.) These will regrow during the next molt. In the meantime, the hermit crab will be unable to eat.
Hermit crabs eat by picking up food with their large claw. They move the for toward the mouth and guide it in using the small claw. If your hermit crabs lack these appendages, they’ll need to be hand-fed.
Hermit crabs are not susceptible to any species-specific diseases. They also do not develop common health complaints that plague mammals, like cancer. Hermit crabs can still grow sick, though.
As mentioned, this may be part of a vicious circle. Hermit crabs that stop eating and drinking grow unwell; not eating and drinking magnifies these health concerns. Stress and an inappropriate environment can sicken hermit crabs.
Check that your hermit crabs are not too hot or too cold in their habitat. Ensure they are enjoying an appropriate balance of darkness and light. Provide company and stimulation as bored hermit crabs grow withdrawn and sick.
How to Get a Hermit Crab to Eat
A hermit crab that refuses to eat is not sustainable. Skipping one meal is not a problem, but if the loss of appetite starts to run into several days, you’ll need to address the issue. Here’s how:
Offer Different Food
Variety is the most important element of the hermit crab diet. In the wild, hermit crabs scavenge from different food sources. Most of these are unappealing to humans, but hermit crabs enjoy having the freedom of choice.
As per the Journal of Experimental Marine Biology and Ecology, hermit crabs frequently ignore the food they consumed less than 24 hours earlier. They would rather wait for a different taste experience.
No matter how much your hermit crab enjoys certain foods, never subject them to the same meal day after day. Always keep an array of different foods on hand to prevent them from growing bored.
Make Existing Food More Tempting
It may not always be possible to find unique food. Familiarity can breed contempt when it comes to nourishment. Spruce up existing foods to make them more appealing. Sweet flavors and sensations work well.
If your hermit crabs ignore fresh fruit as they ate it yesterday, glaze it with honey, natural jam, or preserves. The sweet scent will capture the imagination of your hermit crabs. They will likely rapidly descent upon their meal, demonstrating a renewed zeal for this previously ignored food.
Hand-feeding could be a way to tempt your hermit crabs into eating. If your hermit crab has shed its claws, this will be essential. As discussed, hermit crabs cannot feed themselves without two functioning chelipeds.
Initially, try offering your hermit crab a small amount of food on a plastic spoon. Plastic is always better than metal; the latter material can provoke sensitivities in hermit crabs. Hold the food close to the antennae and see if it piques the interest of your hermit crabs.
Try handling your hermit crabs and encouraging them to eat from your hand. Apply a liquid food to your finger or leave the snack in the palm of your hand.
Only do this if your hermit crabs trust you and accept handling. If your hermit crabs are already stressed, this will aggravate the issue further. Pinching is likely to follow.
My Hermit Crab is Not Drinking
If your hermit crab is suddenly avoiding water, ensure that you didn’t provide tap water. This is toxic to hermit crabs due to the presence of chlorine and copper.
Hermit crabs like tepid water. On a hot day, you may want to put ice cubes in drinking water to prevent overheating, but they’ll dislike this experience. Their body temperature may drop to uncomfortable levels.
Hermit crabs drink water and bathe in it. This means that the water may be messy, containing traces of fecal matter or shed limbs. Not all hermit crabs care about this, but some are fussier than others.
Ensure that your hermit crabs can still get in out of their water supply. Some hermit crabs drink by scooping water into the mouth using the claws. More commonly, they climb inside the water and submerge completely.
Hermit crabs cannot hold their breath indefinitely. Left in water without a means of escape, hermit crabs will drown. They need ropes or ramps to get in and out of a water source. If the hermit crabs no longer trust these entry and exit points, they may avoid water altogether.