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why is my new hermit crab not moving?

Post-Purchase Stress (PPS) And New Hermit Crab Behavior

(Last Updated On: February 17, 2023)

Post-Purchase Stress in hermit crabs is an extreme reaction to being moved from nature to an unfamiliar living environment. Being transferred from their natural environment, transported significant distances, and placed in new homes is an unsettling experience for hermit crabs.

Transitioning hermit crabs from a life in the wild to captivity leads to extreme lethargy, burrowing activity, loss of appetite, and limb amputation. Post-Purchase Stress (PPS) or Post-Purchase Death Syndrome (PPDS) is a leading cause of death in newly acquired hermit crabs.

Identifying these problems allows you to assist the hermit crabs with de-stressing. It’s recommended that you provide an isolation tank (ISO tank). The ISO tank should have humidity and temperature ranges set at the lower end of its needs to make the transition easier.

Hermit Crab Post-Purchase Stress Definition

Post-purchase stress, or post-purchase death syndrome, covers a range of issues that a hermit crab might display after transitioning from one environment to another.

A study in Scientific Reports found that hermit crabs could experience anxiety due to stressful situations. For this reason, many owners argue that PPS is caused by emotional distress.

PPS in hermit crabs is caused by their physiological inability to adapt to rapid environmental changes. Animal Biology found that terrestrial hermit crabs are sensitive to temperature changes.

Whether PPS is caused by psychological stresses or physical issues with environmental factors, it’s still dangerous. Post-purchase stress can lead to serious illness and premature mortality.

Hermit crabs with PPS can experience the following:

  • Extreme lethargy
  • Limb loss
  • Loss of appetite
  • Agitation and aggression

Attempts to hide in substrate or escape are common among newly acquired hermit crabs.

New Hermit Crab Behavior

Why Is My New Hermit Crab Not Moving?

Hermit crabs are nocturnal creatures, so you need to understand their routine rather than making a rash judgment about your hermit crab not moving. 

There could be rational reasons one of your hermit crabs isn’t moving, including:


A hermit crab sleeps during the day to avoid drying out in the heat. A sleeping hermit will be found in an out-of-the-way part of its habitat, tucked inside its protective shell.

While sleeping, a hermit crab will keep its antenna close to the roof of its shell to detect predators.

Humidity Levels

High levels of humidity or heat inside a hermie’s shell may cause it to sleep externally to the shell. If that happens, you’ll find your hermit crab lying motionless in its tank.

However, a sleeping hermit crab will move if you pick it up. If your hermit crab doesn’t move when you lift it, the humidity levels could have rendered it sick and motionless.  

Molting Exoskeleton

Molting involves a hermit crab shedding its old exoskeleton to grow. It’s an energy-consuming process, which is why a hermit crab will be motionless.

It’ll often bury itself for protection, so never move a hermit crab when it’s molting.

Why Is My New Hermit Crab Not Eating?

According to Zoological Studies, hermit crabs have little extreme cold or heat tolerance.

When faced with uncomfortable climatic conditions, hermit crabs may become lethargic and lose interest in eating. Figuring out if a hermit crab has stopped eating isn’t easy as they’re not big eaters.

If you’re concerned that your hermit crab isn’t eating, it may be eating at night. To check if this is the case, smooth the sand around its food and water sources.

If the sand is still smooth in the morning, the hermit crab isn’t eating. Of course, this works best when it’s isolated from its tank mates.

As well as post-purchase stress, hermit crabs can experience suppressed appetite due to illness or molting. If your hermit crab is molting, you may notice that it doesn’t move as much.

Likewise, it may bury itself in the substrate to molt in safety. Ideally, a hermit crab preparing to molt should be isolated from other hermit crabs to minimize stress and disruption.

My New Hermit Crab Buried Itself

Perhaps you recently bought a new hermit crab and introduced it to the main habitat. Then, it buried itself and won’t come out. Hiding, retreating into its shell, or burying itself are common signs of PPS.

There are other reasons why a hermit crab might bury itself, including:


If your hermit crab is molting, it’ll stay buried throughout the process.

The molting process takes 1-2 months, so be patient and don’t move it. Hermit crabs are fragile during this time, and moving them could result in injury.


It’s easy to forget that hermit crabs are burrowing animals.

They create tunnels and burrows throughout the day. By burying itself in the tank, your hermit crab replicates its natural environment.

Looking for Food

It may be that a hermit crab is burrowing, tunneling, and burying itself in search of food.

Wild hermit crabs dig to locate meals. In domesticity, digging in search of food could signify that your hermit crab lacks nutrients. So, mix up its food to see if that rectifies the behavior.

why is my new hermit crab not eating?

New Hermit Crab Not Moving – What to Do

Post-purchase stress is likely part of why your hermit crab has stopped moving or has taken to hiding. In this case, you must assess the habitat.

Unfortunately, it’s impossible to know exactly how a hermit crab was transported when mitigating PPS. You must assume that a new hermie experienced a rough ride and needs to be gently introduced.

Contributing factors to PPS in hermit crabs usually include:

  • Extreme stress during capture and transportation
  • Suboptimal conditions in many pet stores

A hermit crab could die if the stress has been prolonged or the climatic changes between their original, transitional, and domestic environments are too great.

So, introduce the hermit crabs to the main tank via an ISO tank.

How To Make An ISO Tank

An isolation tank should have the same things as the main habitat, but the climate should be different. The isolation tank should have the following:

  • Ample, varied food sources
  • Moist, mixed substrate three times deeper than the size of the hermit crab.
  • Water sources, including freshwater and saltwater
  • Toys for climbing
  • Hiding places

If you ensure that the isolation tank has these resources, a new hermit crab will have the best chance of de-stressing and acclimatizing to its new life.

Set the temperature and humidity to the lower end of its needs before introducing a new hermit crab to the isolation tank. That way, the change won’t shock if its previous environment was cold or dry.

Over 3-4 weeks, gradually raise the temperature and humidity levels in the isolation tank until they match those in the main tank. This period of acclimatization should allow your hermit crab to rest and de-stress.

A hermit crab with post-purchase stress may display lethargy, burying behavior, and aggression. Also, it may stop eating and show signs of illness.