The Land Hermit Crab Owners Society recommends that hermit crabs only be removed from their habitat for an occasional visual inspection or photo.
This is one of the most contested recommendations in our community.
The LHCOS recommendation is based on what research has taught us thus far. We are still learning, research is still being conducted and we are following it closely.
- Land hermit crabs require humid air to breathe. When the relative humidity drops below 70% the gills begin to dry out. Over time the gills will become irreversibly damaged. How much damage they can sustain before death is not known.
- Land hermit crabs are prey animals. Birds and other animals pull them from their shells and eat them. They do not recognize you as non threatening when you swoop in and pick them up and carry them off, like a bird would do.
- Land hermit crabs need places to hide from predators. When they run around the floor frantically it is not because they are having fun, it is because they are suddenly in a foreign world and have no idea where a safe place might be. They immediately scurry under furniture, they need to feel safe.
- Crustaceans do not share human emotions. While they do need conspecifics, they do not need human companionship.
Land hermit crabs pinch when they feel threatened, either from fear of being preyed upon or fear of falling. Handling your hermit crab while it is running around frantically trying to find a safe place is a good way to get pinched. Hermit crabs can easily break skin and once they clamp down, they will not let go until the threat is gone.
Whether being dropped from someone’s hand or from falling off of furniture, a hard fall can be lethal. The crab may suffer internal injuries or the shell may break and puncture the abdomen. In the wild, hermit crabs do drop from trees but are typically dropping into soft sand or leaf litter.
Hermit crabs are escape artists. When allowed to roam outside of the tank there is an increased risk of the hermit crab getting lost. Finding a hermit crab that doesn’t want to be found is harder than you might imagine.
Clothing and bedding have soap and fragrance residues on them. In addition to whatever you encountered during the course of the day. If a hermit crab is crawling on you or your bedding, clothes, etc they are picking up all of this residue and carrying it back into their tank, into their food and into their water.
Carpet and flooring is full of chemicals, bacteria from your shoes and other pets tracked in from outside. If your hermit crab is crawling on your floor they are picking up all of this residue and carrying it back into their tank, into their food and into their water.
If you have other pets you may have fleas in your house and not realize it yet. Flea drop are lethal to hermit crabs. If you treat your pets with flea drops your hermit crabs should be kept away from your fur babies. Wash your hands before handling your hermit crabs or anything in their habitat if you have been touching your cat or dog who has been treated for fleas. This is a good practice in general but a must where flea drops are concerned.
This is not where you decide that you will give your hermit crab a bath before putting him back in his crabitat to justify taking him out in the first place.
But what about Carol and Jon?
Carol and Jon are unique. Talk about relationship goals! We aspire to be as successful as Carol has been. Jon inspires us to continue our research and deepen our understanding of land hermit crabs so that we can continue to provide the best possibly captive life.
Carol has not modified her care routine much from the early days but Jon adapted to life in captivity. No one is really sure how Jon has survived in captivity so long, even Carol herself! Carol and Jon live in Miami. During the day Carol allows Jon to roam under her watchful eye. She does not hold him or play with him while he’s out. The rest of the time he is in his humid crabitat.
Until we understand him better, as well as the long term effects of gills drying out over and over again, we can not in good conscience say it is safe to allow your hermit crabs to roam in your house. There is no demonstrable benefit that justifies the risk.
What about the hermit crab species that are primarily forest dwellers?
Some species of Coenobita do spend the majority of their time in a coastal forest. Hermit crabs rely on the water kept in their shell to re-moisten their gills when they venture from the ocean. The water slowly evaporates or leaks out and must be replenished or the hermit crab will eventually die due to its gills drying it out. Forest dwelling crabs find puddles of brackish water to refill their shell. They can even use their setae to draw moisture from the substrate and into the gill chamber to moisten their gills or into the pericardial sac.
You might encounter pictures of really big purple-colored hermit crabs being non-nonchalantly handled by their keepers on their palms while browsing the internet. These crabs are most likely Coenobita brevimanus or Indos and they are indeed one of the forest-dwelling crabs. They live in tropical Asian countries such as Indonesia and thus the pictures are also likely originating from those countries where the ambient temperature and humidity outside of their crabitat is comparable to inside. Having said that, there is growing awareness among the Asian hermit crab keepers that the crabs are indeed much happier being left alone rather than being handled about, no matter how docile they may seem.
If you follow the LHCOS recommendations for setting up a proper habitat you will have pools deep enough for your hermit crabs to replenish their shell water. This will protect them for awhile if they escape. It may also help protect them if you take them out, providing they had shell water when you pick them up and providing you don’t spill it out when you pick them up.
Sadly, the owners who are the most determined to take their crabs out are most often young and uninformed about proper care requirements. Their crabitats lack humidity and deep pools. These crabs are the most at risk when removed from their habitat.
Hermit crabs walk many miles at night foraging for food and migrating to the ocean/forest. You can fill this need by providing them with a solid plastic rodent wheel or saucer. They can and will use it, often for hours at a time and often queuing up for a turn!
Find a wheel on Amazon: https://amzn.to/3eem5q0
|The Pericardial Sacs of Terrestrial Brachyura||Dorothy E. Bliss||1963|
|On the Ecology of Coenobita Clypeatus in Curaçao: With reference to reproduction, water economy and osmoregulation in terrestrial hermit crabs||Erik Wilde||1973|
|Functional morphology of the primary olfactory centers in the brain of the hermit crab Coenobita clypeatus (Anomala, Coenobitidae)||Marta A. Polanska1 & Tina Kirchhoff2 & Heinrich Dircksen3 & Bill S. Hansson4 & Steffen Harzsch2,4||2020|