Tag Archive for hermit crab care

Airborne Irritants and Hermit Crabs

Hermit crab's gills are sensitive to airborne irritants

Hermit crab’s gills are sensitive to airborne irritants

Land hermit crabs breathe through a modified gill. It is important to protect the gills from strong fragrances, essential oils, candles, household cleaners, chemicals, smoke insecticides and other airborne irritants.

Be mindful of what you spray or use near the crabitat even if your tank is fully sealed. Residual product may still be in the air when you open your tank.

If you are forced to have your home sprayed for insects ensure your tank is fully sealed with saran wrap or something similar. Allow the house to air out at least 24 hours before unsealing your tank.

Local Reps European Invasion – Hungary!

Local Representative – Hungary

That’s right, HUNGARY! We have our first European Local Representative joining us.  Please welcome Veronika Barany Berthane to the team!

This mother of two became the owner of a couple hermit crabs when a friend of her child no longer wanted them. With a little bit of searching she found our Facebook group. After joining our group and learning all she could about hermit crab care she decided to help others in her region by translating our care practices and establishing a hermit crab care blog and a Facebook group in Hungarian. Veronika also posts pictures of her hermit crabs babies on Instagram. 


From Veronika:

I couldn’t have asked for a better care group, there was so much information to process, I had an endless list of questions. The admins and the group members helped me so much, answered my million questions, gave me lists, helped me correct my mistakes. It’s an awesome group. I’d like to give back by helping others who would like to keep land hermit crabs. I made a small group in Hungarian, a blog about them with a link to my instagram where I have pictures of my crabbies.

Hungarian land hermit crab care group on Facebook:


Hungarian land hermit crab care blog:


Veronika on Instagram


Relocating to a new home with your hermit crabs

A change of housing is easy for a hermit crab but for people it takes a bit more planning! Photo credit Volapardus http://volapardus.tumblr.com/

A change of housing is easy for a hermit crab but for people it takes a bit more planning!
Photo credit Volapardus

Relocating to a new house is something all humans do at least once in their life. Sometimes the move is planned and sometimes not so much. Relocating with hermit crabs can be a bit more challenging that moving with other pets. While I’m certain there are other ways to ensure the move goes smoothly we are only going to cover some basics here.

First of all, do not move your tank with the substrate and crabs still in it. The biggest danger is the collapsing of molt burrows. Even if you don’t have hermit crabs underground you risk the bottom busting out of the tank while you are carrying it.

If you are relocating with advance notice you can begin to prepare for your move months in advance.
Begin by setting up a temporary crabitat in a storage bin, depending on the number of hermit crabs you have you may need more than one. See the link at the bottom of the article for a video on setting up a storage bin crabitat. I would recommend very shallow substrate so your crabs are not underground when moving day arrives.

At this stage if you are three months out or less from moving day start relocating your hermit crabs into the temporary crabitat. Only move the hermit crabs that are above ground at this stage.Molting hermit crabs will be moved to the temporary crabitat as they surface. Ideally all molters will be up before your move and safe in the temporary crabitat.

If moving day arrives and you still have hermit crabs underground molting you will be forced to dig them up.  You will want a separate temporary crabitat set up for them so you are not placing molters in with the rest of the colony. Digging must be done slowly and carefully so as not to damage a soft exoskeleton. Any uneaten bits of old exoskeleton should be moved with the crab so it can continue eating it. Do not attempt to re-bury the hermit crabs in the temporary crabitat, place a bowl or hut over them for privacy. If you only have one or two molters you could place them in a small container with a bit of moss and a holes in the lid. Gladware type bowls are good for this but you can use something like a mason jar also, just so there is an air hole. These small containers can be placed in the temporary crabitat. Be sure they are secure and won’t tumble around in the bin.

Moving without advance notice will also require you to set up a temporary crabitat in a storage bin. Again use shallow substrate so no hermit crab is underground while in transport. Hermit crabs that are above ground can be moved directly into the temporary crabitat. Molters will have to be very carefully dug up and placed into individual containers with a bit of moss. Digging must be done slowly and carefully so as not to damage a soft exoskeleton. Any uneaten bits of old exoskeleton should be moved with the crab so it can continue eating it. Gladware bowls or Mason jars with holes in the lid could be used. Place these containers in the temporary crabitat and secure them so they won’t tumble around in the bin during transit.

How to set up a storage bin as a temporary habitat

A storage bin can be used as temporary housing for your hermit crabs during a move - Photo credit: Donna Boo

A storage bin can be used as temporary housing for your hermit crabs during a move – Photo credit: Donna Boo

Setting up a proper crabitat

Let’s look at how to set up a proper hermit crab habitat, which we refer to as a crabitat.

Basing your tank set up on what you saw at the petstore or mall cart where you may have purchased your hermit crabs is a recipe for disaster. Kritter Keepers and wire cages are death boxes and should never be used.

Listed below are the primary components of a proper set up and we will discuss them in detail. If you are not willing to equip the tank properly you should return your hermit crabs or rehome them, they will not thrive without a properly set up habitat. Captive hermit crabs can live over 30 years in the proper habitat. Most hermit crabs die either in the first month of ownership, during the first molt of ownership or within the first year to 18 months.  So yes, they can technically ‘survive’ in poor conditions but why on earth would you purposely do this to an animal???

A simple list of the items you will need to properly outfit the crabitat. There are low cost options for most of these items.

  • Tank
  • Lid
  • Light*
  • Heat
  • Substrate
  • Gauges
  • Bowls
  • Climbers
  • Hiders
  • Plants and Vines

The tank itself should be glass or lexan and large enough to comfortably house your hermit crabs. A MINIMUM of 2 gallons of space per small or medium hermit crab but 5 gallons per crab is much more humane. Large and jumbo crabs will need much more space, 10 gallon minimum. A 10 gallon tank is too small for even one large or jumbo crab. Plan for the future when purchasing your tank, allow for the growth of your crabs or additions to the herd.   A used tank is perfectly fine and will greatly reduce the cost of supplies.

The tank must have a lid that retains humidity. A screen lid with glass, lexan or plastic wrap on top is what is typically used. Hermit crabs require humidity to breathe. Opening the lid for feedings and water changes each day usually provides enough air exchange. Fresh air flow reduces mold, mildew and fungus growth.

Light is required, whether they are used as your heat source or not. Hermit crabs require a normal 12 hour cycle of light and dark, it is vital to the molt process. If your crabitat is in a well light room that will meet the need of daytime light. Do NOT place your tank in directly sunlight!

UVB is believed to extend the life span of captive hermit crabs. UVB bulbs must be mounted in such a way that there is no glass or plastic barrier between the bulb and the hermit crabs. Most people mount the lid inside the tank.  Bulbs must be replaced every 12 months.

For nighttime viewing, LED in red or blue is safe. Your hermit crabs do not require a light at night.

Hermit crabs require warm temperatures. This can come from overhead lights or from heat pad (often called under the tank heater or UTH) which is placed on the wall of the tank and not under it. Over head lights or heat emitters are not recommended for inexperienced pet owners. They make it challenging to maintain the correct environment in the tank.

Ways to heat your crabitat

Global Temperature and Precipitation Maps by Month

Gauges are the only way to monitor and maintain proper heat and humidity levels. The tank temperatures should be a range of 75F to 82F.  72F is the absolute minimum and your tank should not remain at this temperature long term. A temporary dip or spike in temperature is not cause for concern. A range means that your tank should have areas of different temperatures. Some species seem to enjoy slightly warmer temperatures but the common clypeatus is happy in the 75-82F range. Check the substrate temperature as well to make sure it is not too hot. Overly warm substrate will kill molters or discourage molting. Humidity ranges should be 70-80% this is relative humidity. Occasional higher humidity is not cause for concern but maintaining excessively high humidity could lead to flooding or lethal bacteria due to over saturation of your substrate. Your analog hygrometer will need to be calibrated before use. Wireless, digital gauges are relatively cheap and are more accurate than analog gauges.

Substrate should be a mix of 5 parts play sand and 1 part eco earth. The ideal mix will keep the sand moist throughout. The consistency should be so that you could easily make a sand castle. That means that molting burrows will not collapse from drying out. We suggest using a brackish water to expand the eco earth bricks. This will help reduce the chance of mold. The eco earth should be DRY when mixed into the sand so you don’t end up with water logged substrate at the beginning. You can always add water once the crabitat environment is stable, if needed. In many cases it is not needed. Starting with too wet substrate will lead to flooding and/or bacterial blooms. Mix your substrate dry, close up the tank with the lid and all the decor and allow it to stabilize for 48 hours. If the humidity is too low you can mist the substrate. Then wait another 24 hours and check the humidity again. It is much easier to add moisture to the substrate than it is to dry it out once it is in the tank.

The eco earth will help maintain humidity but you may need to add some moss pits if your levels are too low. Not all moss is safe so be sure to check our list: Which types of moss are safe for my hermit crabs?

Substrates for hermit crabs

Three bowls will be needed. Two of the bowls should be deep enough to allow your hermit crabs to submerge themselves. One should be fresh water and one should be ocean water made with marine grade salt mix. All water that comes in contact with your hermit crabs must be treated to remove chlorine, chloramines, ammonia as well as other chemicals. The third bowl will be for food. These don’t have to be reptile dishes specifically but they should be something that your smallest crabs can easily enter and exit. Many people use disposable Gladware type bowls for water pools. We recommend placing a rock, fake plant or coral in the pool for the smaller crabs to climb out.

Places to hide, things to climb on, as well as plants and vines are important to create an environment that is stimulating and enriching for your hermit crabs. Huts do not have to be made of coconut shells, many things will work. The same holds true for things to climb on. There are lots of DIY ideas or less expensive ideas for creating vertical climbing opportunities. Fake plants and vines from a craft store will work as well as the ones you find at the pet store. Some live plants are safe for the crabitat but your hermit crabs will most likely kill them.

Creating additional levels in your crabitat to maximize usable space

Your goal should be to create an environment that is as close to what hermit crabs experience in nature as possible. Hermit crabs live primarily on beaches, so think tropical!

Here are some examples of properly set up crabitats:

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Coenobita Pereiopods

In hermit crabs, the fourth and particularly the fifth pereopods are reduced, usually remaining within the confines of the gastropod shell and hence are not used for walking. These appendages do however becoming important when the hermit crab attempts to right itself, providing anchorage within the shell. Further, the fifth pereopod has become specialised as a gill cleaning appendage, often resting within the gill chamber (Bauer 1981). On the abdomen only the left pleopods are retained (Poore 2004).[1]

Hermit crabs used specialized setae on the their maixillipedes and fifth pereiopods for most grooming but used the unmodified first, second, and third periopods as well. Most brachyuran grooming was performed with modified setae on the the third maxillipedal palps and eipods, with a row of simple setae on each chelipede merus, and with the chelipede fingers.

The third maxillipedes and fifth pereiopods performed the majority of movements, including all of the more complex actions, and were suprisingly dexterous. Coenobita clypeatus devoted most of it’s grooming energy on the eyes and anntennules and did so with the mesial surfaces of the dactylus, propodus, carpus, and distal merus of the third maxillipedal endopods.

The three pairs of walking legs (chelipedes included) groomed themselves by scrubbing against each other in various combinations of two or three appendages. In addition, the fingers of the minor chelipede picked at the surface of the major chelipede. The chelate fifth pereiopods were quite flexible and extended as far forward as the chelipedes. The fifth pereiopods also groomed most of the central and posterior carapace, including the branchial chamber, and much of the abdomen. The fifth peeriopods groomed much of the shell’s interior, particularly the columella and innner and outer lips, as well as the exterior lips.These appendages did not function exclusively as grooming organs, as they also use their laterally situated gripping scales to brace the body against the shell (Johnson 1965, Vuillemin 1970).

After every few grooming acts, the fifth pereiopods moved anteriorly, in unison. to meet the two third maxillipedes, which were extended posteriorly beneath the body. The plumodenticulate and serrate setai of the posterior appendages were then scrubbed by the maxillipedes. The third maxillipedes, in turn, were scrubbed against each other and/or against the second maxillipedes after a grooming bout. The interior mouthparts had a self-cleaning function as well.

Thus, the maxillipedes groomed the anterior portion of the body (especially the sensory structures), the walking legs groomed each other, and the fifth pereiopods scrubbed the most posterior areas. Two movements were, at times, performed simulanteously, e.g., mutual leg scrubs and anntennule grooming. Although grooming may occur at any time, it was most frequentl and intense immediately after a ran and was often performed in standing water if it was available. Water is clearly an important debris-flushing medium. The grooming setae, parrticuarly the serrate setae, may also serve in a sensory capacity (Derby 1982).

Foam bathing, in which bubbles produced by the mouthparts disperse fluid about the body, occurred in partially submerged or emergent crabs. This action has been variously interpreted as a method of thermoregulation, pheromone distribution, water reserve aeration, or cleansing.(Altevogt 1968, Wright 1966, Lindberg 1980, Jacoby 1981, Schone & Schone 1963, Brownscombe 1965). [2]

Pereiopods are primarily walking legs and are also used for gathering food. Those pereiopods which are armed with a claw (chela) may be referred to as chelipeds. The moveable fingers of a claw are known as dactyls. The pereiopods bear the sexual organs (gonopores), which are the third pereiopod in the female and the fifth pereiopod in the male.

Anatomy of hermit crab leg "pereiopod"

Anatomy of hermit crab leg “pereiopod”

Land hermit crabs are able to regenerate lost appendages with molt.

We are building image galleries of specific body parts. If you have high resolution, clear photos that you would like to donate to this project please contact us via email: crabstreetjournal at gmail dot com

Overview of the anatomy of a land hermit crab (Coenobita)

Photo Credits:

Amber Miner

Lisa Dawson

Marnel Rodriguez

Vanessa Pike-Russell

Stacy Griffith


  1. Dardanus megistos by Storm Martin 2012
  2. Grooming structure and function in some terrestrial Crustacea

Ask Milo – I need some DIY hermit crab toys ideas

Anna asks:

I have been having some trouble finding a good way to make some fun toys that my hermit crabs would love. My Crabitait is plain With nothing for the hermit crabs to really do. I have some branches that they don’t like and a lego 2nd floor which they dont go on unless i put them on there(though they LOVE to hangout under it). Plus the toys at the pet store are to expinzie for my buget. I want them to love there cage. Do have any ideas for homemade toys that would make my hermit crabs have a better time in my cage and make it feel more homie?

Our members are very creative at making DIY toys and fun things for their crabitats. The best way to get ideas is to ask your question on our forums! Here is a tutorial on how to make your own mangrove tree. Here is another article on cost cutting tips for setting up your crabitat.

Happy DIY!

Your friend in a pinch,


Atypical things hermit crabs can eat

Hermit crabs are omnivorous scavengers in the wild. There are lots of different foods that a hermit crab can eat. We have several different food lists for commonly fed items. Check out a few of the atypical things that hermit crabs can eat:

Feces – herbivorous animal droppings. In Quirimba hermit crabs are known to eat human waste as well.
Fish flakes or pellets
Cuttlebone – great source of calcium
Bonemeal – great source of calcium
Cicadas and their exoskeletons (most other bugs too)
Worm castings

Cicada exoskeletons

Cicada exoskeletons

Compressus eating guinea pig feces

Compressus eating guinea pig feces by Stacy Griffith

Hermit Crab Surface Molt

Hermit crabs typically go about their molting business below ground away from your prying eyes and nosey tank mates but this isn’t always the case. Sometimes you will find yourself with a surface molter on your hands. Surface molts can be very cool for you but additionally stressful for the crab.

Coenobita clypeatus - Purple Pincer Hermit Crab Surface Molt

Coenobita clypeatus – Purple Pincer Hermit Crab Surface Molt

C. compressus surface molt. Top most leg is a newly regenerated limb.

C. compressus surface molt. Top most leg is a newly regenerated limb Photo by Nichole Edwards.

Let’s look at the best way to handle a surface molter.

  • First do not touch or move the crab! (unless you feel you must to ensure it’s safety)
  • Second find a way to securely isolate the crab.
  • It is extremely important that your tank temperature and humidity are in the proper ranges at this time.
  • Do not mist a soft hermit crab, there is danger of causing an infection by over wetting the soft exo.
  • Do not remove the shed exoskeleton (skin), your molter is going to eat that and it’s important that he does!
  • Do not place your molter in total darkness. Normal light cycles are needed!
ISO bottle should be pushed all the way to the bottom of your substrate so there is no way for another crab to burrow in from below.

ISO bottle should be pushed all the way to the bottom of your substrate so there is no way for another crab to burrow in from below.

In place isolation of a surface molter can be accomplished by cutting the bottom off of a 2L plastic bottle and then placing it over the molter and pushing it down (gently!) into the substrate, all the way to the bottom of your tank if possible. This will keep tank mates from cannibalizing the molter while it is soft and defenseless. Remove the lid from the bottle top to allow air flow.  If you can’t get the bottle all the way to the bottom of the tank, keep an eye out for signs of other crabs trying to burrow their way in.

Kritter Keeper used in main tank as an ISO for surface molters

Kritter Keeper used in main tank as an ISO for surface molters

If you simply can not securely isolate the surface molter, you may be forced to move them. You need to have some sort of container ready, preferably something that can stay in the same tank where the molt has occurred. Very small kritter keepers are ideal for this as they have secure lids but are vented for air flow. As gently as possible move the molter AND the shed exo to the isolation container. Do not poke, prod or otherwise futz with the molter.

Post Molt Photo by Jenny Velasquez

Post Molt Photo by Jenny Velasquez

When the molter begins moving around on his own you can gently move him from the 2L bottle enclosure to a larger isolation tank stocked with food and water and a hut. When your molter has fully hardened up it’s time to go back to the main tank. Monitor the molter and the tank mates for signs of aggression. If you witness ongoing aggressive behavior, place all crabs upside down in your water pools. This will rinse off the molting scent and everyone will smell the same again. Unless there is a problem, bathing is UNNECESSARY and should not be done. Aggressive behavior is an indicator of a bigger problem, usually over crowding or inadequate diet.

I understand that it is very fascinating to be able to watch the molt process happening but remember your presence is threatening to the hermit crab at this time. If you want to take photos, do NOT use the flash! Limit your photo taking and time spent hovering and try really hard to let your poor little crabbie do his molting business in peace and quiet.

Coenobita rugosus post surface molt munching on some delicious exo:

Tony Coenobita

Tony Coenobita's rugosus that he has owned for 15 years!

Tony Coenobita’s rugosus that he has owned for 15 years!

Hello, I am Tony from Hong Kong.

Land hermit crab can found in pet shop, but there is not much information about them. When you ask the sales how to take care of them, they will tell you to give them a little bit of water in the tank is ok and give them bread for food.

I followed this method when I was a kid, of course they are all out of shell and died after few weeks.

Some people even do not know they are different from marine hermit crab and will put them into aquarium.

I think me and land hermit crab have a kind of so called ‘destiny’.

I studied Japanese in university and one day my parent bought me a Japanese book which teaches kid how to take care of small animals, I found land hermit crab on this book and start to search information in Japan website.

I found many information for them, it just like a found a treasure. There are so much detail information. Then I also start to search more in English website.

I want to set up a website in Chinese. I want to gather information from English and Japanese so to give everyone a more correct way to take care of land hermit crab.

My thinking at that time was because in Hong Kong, there are no land hermit crabs live in wild, they are all collect from overseas and we cannot help to release them back to wild. That mean once you bought them back home, you must do your better to treat them, to keep them as long as.

I spend almost one year to set up and start www.tonycoenobita.com in 2003, I am very happy that later this website help a lot of people in Chinese to know more about them.

Of course when I start my first crabitat, I lost some crabs also. Every time I lost a crab I will think what happen? Is it environment problem? Molting problem? Sea water problem etc……and then improve the crabitat.

I think all the beginner had this experience and for sure we need time to improve but the most important thing is our mind.

I saw some people bought tens of crab, especially many people like to buy big size and they call themselves crab lovers and very proud of it.

But they never check the crab one by one every day, they even do not know which crab is molting. They just put all of them into a tank and let it go, when they found a crab died, they bought new one to replace……it is crazy!!

Many people said no demand no supply that is true. However, when we see the PP with Coral is over 30 years (39 years in August), we all know that land hermit crab can live over 30 years even in crabitat. I also have a rugosus with me now 15 years in August(see attached photo).

So, if everyone take a right attitude to take care of them, everyone can keep his/her crab over 30 years, I think the demand will be decrease, right?

In the wild, now many crabs have been found they have to use rubbish instead of shell for their home. Catch one crab mean also catch one shell, we all know that. I really hope that one day, Conservation management strategies will be put in many countries for land hermit crab just like Japan. In Japan, only legal supplier can catch them in wild in regular amount. This can help land hermit crab not being over harvested.

Tony Coenobita WEBSITE: http://www.tonycoenobita.com

Tony Coenobita BLOG:  http://tonycoenobita.o-oi.net/

Tony Coenobita FORUM:  http://www.tonycoenobita.com/discuz/index.php

Tony Coenobita FACEBOOK:  https://www.facebook.com/pages/香港陸寄居蟹研究室/518326288229682

Tony Coenobita TWITTER: @TonyCoenobita

Protect Coenobita Overharvested Campaign:  http://campaign.tw-npo.org/sign.php?id=20141219215315

Ask Milo – Removing mold or mildew from wood

Anna asks:

How do i get white fluff mold from my old cage off of my half log hut with out burning it?
Dear Anna,
The white fluff mold is not at all safe for your hermit crabs!. If the half log hut is small enough, I recommend placing it a pot of boiling water. Boiling it for 15 minutes or so should be good. Then place it on a cookie sheet and turn your oven on a low setting like WARM or 200F. This will provide a low heat for thoroughly drying the half log hut. This temperature is safe and will not burn the wood. If you don’t feel safe doing that I would suggest placing it outside in the bright, hot sun for a couple days.
Hope that helps!
Your friend in a pinch,