Why is my Hermit Crab so inactive?

C brevimanus

C brevimanus

Originally written by Vanessa Pike-Russell-Updated by Stacy Griffith

There are a few reasons your hermit crab may be less active than you expected.

  1. Natural instincts
  2. Incorrect temperature and/or humdity
  3. Crabitat does not provide an interesting, enriched habitat
  4. Pre- molt
  5. Impending death

Land Hermit crabs are primarily, but not exclusively, nocturnal creatures. That means that in the wild they sleep during the day and are active at night. This allows them to escape the drying heat of the sun as well as predators. They hide away in the leafy foliage or cool areas and are active once the sun has set and the moon is out, roaming about in groups of 100 or more in search of food. If a shadow passes over your hermit crab you will see the instinctual reaction of your hermit crab retreating within their shell for protection. Imagine the shadow of a bird passing overhead, wanting you for dinner , wouldn’t you would retreat into your shell to pretend to be just a shell? I would! Spending quiet time near the crabitat will help your hermit crabs get accustomed to your presence. Do your best to avoid throwing shadows over the tank, master the hermit crab belly crawl if necessary!

Another reason for inactivity is incorrect temperature and/or humidity in the crabitat. If the temperature falls below 72F, or the humidity within the crabitat is below 70% your crabs will stay hidden away and less active. It is important to keep a comfortable environment for your hermit crabs as the incorrect environment will slowly kill your hermit crabs.

Is your crabitat boring? One way to increase activity is to create an obstacle course within the tank, using cholla logs or driftwood, coral and/or rocks. Providing an enriching environment will encourage your hermit crabs to explore. They are curious beings and they love to climb.

If your hermit crab is inactive for a long period of time which follows the habit of spending a lot of time in the water dish, your crab may be preparing to molt. Pre molt symptoms vary from crab to crab. Some crabs get slow and cranky, others are busy, some load up on food, others increase their water intake.

The final cause could be impending death. This could be a result of incorrect habitat conditions, incorrect food (nearly all hermit crab food sold in retail stores is toxic) or PPS (post purchase stress).