What to do if my hermit crabs aren't eating?

Why Isn’t My Hermit Crab Eating or Drinking?

Last Updated on October 19, 2023 by Joanne Harper

Pet hermit crabs may stop eating and drinking due to stress, being offered the same foods, a lack of saltwater (muting their sense of smell), excessive noise, and general disturbances.

Hermit crabs can survive without food and water for up to 14 days because they store water in their shells to moisten their gills. This enables them to make it through the molting process.

If you’re concerned that a hermit crab is sick, move its food and water vessels closer. If a hermit crab feels weak, this will make food and water consumption easier for them.

Do Hermit Crabs Eat and Drink Every Day?

Hermit crabs are risk-averse nocturnal animals that emerge when it’s dark.

This is when they seek food and water, traversing the beach and seeking nourishment and hydration. After getting what they need, hermit crabs return to the safety of their burrows.

Pet hermit crabs almost always begin life in the wild because breeding in captivity is rare. They’ll be accustomed to this way of life, so do your utmost to replicate this in captivity.

How Long Can Hermit Crabs Live Without Food or Water?

Hermit crabs can survive for up to 2 weeks without eating or drinking. Basic survival is entirely different from growing and thriving as wild animals.

We assume that hermit crabs can survive for a long time without nourishment and hydration because they burrow for an average of 4-8 weeks while molting, but this isn’t entirely accurate.

While hermit crabs stay under the substrate when molting their exoskeleton, they still eat and drink.

Hermit crabs instinctively know when a molt is impending, so they eat and drink more than usual in preparation. This enables them to add fat to their exoskeleton and store water in their shells.

While molting, hermit crabs sustain themselves on their shed exoskeleton. This ‘recycles’ the essential salts and minerals needed for the growth and calcification of a new exoskeleton.

Also, the water stored in the shell provides hydration until the hermit crab eventually resurfaces.

Do hermit crabs eat every day?

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.

Even land hermit crabs need regular water. They live in hot, tropical climates, so a tank should be heated to 80 degrees, so hermit crabs must hydrate to remain alive.

As well as quenching thirst, drinking water keeps the gills moist. If their gills dry out, breathing becomes more difficult, resulting in suffocation.

Hermit crabs also need protein and calcium for a robust exoskeleton.

My Hermit Crab Won’t Eat

While hermit crabs aren’t greedy animals, they won’t intentionally starve themselves.

Some hermit crabs are pedantic about when they eat. If you provide food at sundown, not all of them will immediately eat. Some prefer to have their meals later in privacy when nobody is about.

As mentioned, hermit crabs are nocturnal animals, so they usually eat food after dark. If you leave food overnight and it has disappeared by the morning, this will be the explanation.

As hermit crabs are natural scavengers, they may also hide their food.

Full Stomach

Hermit crabs eat every day, but they eat in small quantities. If you place large amounts of food in a tank, a lot may be left, creating the impression that hermit crabs have stopped eating.

The hermit crabs may have eaten their fill. Don’t forget that the food you serve in a dish isn’t their only food source, as they may have eaten insects, wood, moss, and algae.

Negative Connotations with Food

Hermit crabs can remember things, recalling negative experiences with food.

According to The Biological Bulletin, hermit crabs avoid food that previously led to sickness. For example, a sudden aversion to fruit may be due to a hermit crab eating buried fruit that went rotten.

Behavioral Processes explains that the scent of food alone can be enough to deter hermit crabs.

Excessive External Stimulation

If 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.

According to Animal Behavior, hermit crabs find their senses dulled by certain ambient noises.

Although hermit crabs don’t have good hearing, they can detect low and mid-frequency sounds. If you’ve moved the tank, they may pick up on external sounds they didn’t previously.

Lack of Saltwater

Hermit crabs need 2 disparate water sources in their habitat: freshwater and saltwater. The latter is critical for feeding, as is appropriate humidity. Without them, hermit crabs can’t smell food.

The Proceedings of the Royal Society explains how hermit crabs use water vapor to activate their sense of smell. Their antennae will start to twitch, and they’ll investigate the food source.

These senses are blocked if the humidity level is below 80% or there’s no marine salt in the water bowl. Hermit crabs won’t eat what they can’t smell, so rectifying these issues may stimulate appetite.

Stress

Almost all new pet hermit crabs go through post-purchase syndrome (PPS). This is a period of intense stress upon transitioning from the beach to captive living.

Hermit crabs remain burrowed under the substrate throughout PPS to de-stress. You mustn’t disturb them because they’ll emerge when they’re ready to eat.

Hermit crabs eat by picking up food with their large claw, moving it toward the mouth, and guiding it with their small claw.

Be aware that stressed hermit crabs may shed limbs, including their claws (chelipeds), which will regrow during the next molt. In the interim, the hermit crab will struggle to eat.

Sickness

Hermit crabs aren’t susceptible to species-specific diseases and don’t have common health complaints that affect mammals. However, hermit crabs can become sick.

Check that your hermit crabs aren’t too hot or cold in their habitat. Also, ensure they get the optimal balance of dark and light to sleep for up to 8 hours and remain healthy.

How To Get A Hermit Crab To Eat

A hermit crab that refuses to eat isn’t going to survive for more than 2 weeks. Skipping one meal isn’t a problem, but you’ll need to address the issue if the loss of appetite is prolonged. Here’s how:

Offer Different Food

Variety is the most essential 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 the freedom of choice.

According to the Journal of Experimental Marine Biology and Ecology, hermit crabs frequently ignore food they consumed less than 24 hours earlier.

No matter how much a hermit crab enjoys certain foods, never feed them the same meal twice in a row.

Do hermit crabs eat when molting?

Make Existing Food More Tempting

Spruce up existing foods to make them sweeter-tasting and more appealing.

If a hermit crab ignores a fruit because it had some yesterday, glaze it with honey, natural jam, or preserves. The sweet scent will be irresistible to hermit crabs.

Most will descend upon the meal, demonstrating a renewed zeal for a previously ignored food.

Hand Feeding

Hand-feeding can assist a hermit crab who has shed or lost a claw.

Initially, offer the hermit crab a small amount of food on a plastic spoon. Hold the food close to the antennae and see if it piques the interest of the hermit crab.

Apply a liquid food to the tip of your finger or leave a tasty snack in the palm of your hand.

Only do this if your hermit crab trusts you and accepts handling. If a hermit crab is already stressed, this will likely aggravate the situation further, leading to pinching.

My Hermit Crab is Not Drinking

Don’t provide tap water because it’s toxic to hermit crabs due to chlorine and copper.

Hermit crabs like tepid water. You may consider putting ice cubes in drinking water on a hot day to prevent overheating, but they’ll dislike this experience because they’re ectotherms.

Hermit crabs drink water and bathe in it. This means the water may be messy, containing fecal matter.

Ensure the hermit crab can get out of the water. Some hermit crabs drink by scooping water into their mouth using their claws, while others submerge in water.

Hermit crabs can’t 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 a hermit crab no longer trusts these entry and exit points, it may avoid water altogether.