Hermit Crabs - What the Pet Store Never Told You

Have you ever walked a boardwalk and noticed how many of the shops have creatures called hermit crabs, which are tiny crustaceans in shells for protection, packed like sardines in huge, wire cages, often without even sand or gravel for a substrate? Sometimes, they don’t even provide these animals with food or water. They can make it seem like hermit crabs are easy to care for, so they can sell more for profit. These beautiful creatures often only last months in human captivity, but in the wild, hermit crabs usually last more than fifty years. Often, boardwalk stores, pet stores, and most other stores that sell hermit crabs do not inform you on what they really need.

For example, most people who sell this precious creature do not tell you that you need a humidity gauge. These can be bought at most pet stores and also on the Internet if you prefer. The humidity should be at least 70% for most species of land hermit crab and should not exceed more than 85%, or mold, which can be deadly to your hermit crab, may start growing in your hermit crab’s tank. To raise the humidity, use a spray bottle with dechlorinated water or spring water and mist it whenever the humidity goes does. The humidity requires frequent watching, so be sure to check it a few times per day. Also, a glass top on your tank will be better as opposed to a screen top, because moisture will be able to escape through the screen. Wire cages usually do not hold enough humidity, either, so a glass aquarium, preferably ten gallons or bigger, is best.

Also, the tiny wire cages and those plastic containers little kids usually keep insects in are not roomy enough for hermit crabs. For a hermit crab, living in one is often like being trapped in your bedroom for days on end and having a temporary break whenever the human decides to take him/her without being completely free to roam wherever the hermit crab wishes. Bigger is always better when it comes to tanks.

It is also wise to have a temperature gauge or a thermometer inside of the tank to be sure it does not get too hot or cold inside of the tank. This often happens in the winter, when humans have their thermostats for their heaters only up to 65° F. Hermit crabs need their temperature to be at least 70° and no hotter than 85°. That’s 21-29° Celsius. To heat the tank, you can use an overhead lamp with an incandescent bulb like the ones you buy for reptiles. Twenty-five watts should be plenty for a ten gallon tank, but bigger tanks can have up to 100 watts. Be sure your hermit crab cannot reach the lamp, or it can suffer from serious injuries and most likely death.

Pet stores and boardwalk shops also often do not tell you that you cannot use tap water. This is because the chlorine in tap water can burn the hermit crabs’ modified gills and eventually kill them. You can either buy spring water from the store, or you can dechlorinate it at home using the same stuff you use for dechlorinating fish water, unless the dechlorinator has stress coat in it, which can actually hurt your hermit crabs and is totally unnecessary for your hermit crab. It will not help your hermit crab in any way, because it is designed only to reduce stress for fish by giving it a slime coat.

Gravel is a big no for hermit crabs. This is because they cannot dig down to molt if you use gravel. It is best to use moist sand, so their molting tunnel holds well. The sand should be at least three inches deep and possibly deeper if your hermit crab is larger. The cheapest way to do this is to buy some play sand from the Home Depot or somewhere similar. If the play sand is outside and wet, it may not be the best sand to use. Do not use the calci-sand at pet stores; when wet, this type of sand can get pretty stinky and just plain horrible. Another type of usable substrate is coco-fiber, which can be bought in some pet stores. Play sand is way cheaper, however, and some crabs do not like coco-fiber.

Molting is serious business for hermit crabs. It is a process where a hermit crab sheds its exoskeleton, which is sort of like its skin and skeleton altogether, and eats it. This lets the hermit crab grow. When it is done eating the skin, it will re-harden, so it will be protected from predators. It is quite stressful, and some hermit crabs do not make it through a molt. Younger hermit crabs have many more molts per year than older ones, but the older ones become more stressed out over molts. You must separate your hermit crab from the others into another hermit crab tank if it has a surface molt, which is a molt that it does not dig down into the sand for. This is because other hermit crabs in the tank will try to cannibalize the other hermit crab when it is so vulnerable. This tank does not have to be as big as the others since the hermit crab will not be active during this time. Be sure to provide the hermit crab with ample sand as well as its other requirements, such as food and water. Do not bother the hermit crab while it is molting, or it can easily die. Also, do not dig up a hermit crab from the main tank that has dug under the sand, because it can be possibly molting and might die from the stress of being handled during a molt.

Hermit crabs also need bigger shells to change into for when they grow too big for their current shell. You should have a variety of shells for the hermit crab to pick from; especially if is a picky crab. Do not use painted shells. The paint will chip off, and the hermit crab will become ill from eating it. Even if your hermit crab does not purposely eat it, it can end up in the water, and the hermit crab will accidentally swallow it.

For food and water, you’ll need three bowls and dishes - one for hermit crab food, one for fresh water, and another for salt water. The salt water bowl should be able to fit a bathing hermit crab. If your hermit crabs are small, you should provide it with something like a rock or a sponge to climb out of the water without drowning, though neither is necessary for bigger crabs. Do not use table salt to make the salt water. This will only kill the hermit crab. Instead, buy some marine salt from the pet store sold for fish, like Oceanic or Instant Ocean.

One thing you ought to also know is that there are different species of hermit crabs, and some of them need special care. For example, the “strawberry hermit crab” (C. Perlatus) needs a bathing bowl that it can fully submerge into. Also, strawberry hermit crabs don’t deal with stress well compared to other species, so they are not for people who don’t have adequate experience with hermit crabs already. The strawberry hermit crab is usually completely red, but it can also have a bit of white, depending on the nutrition of its diet. It is not to be confused with the “purple pincer” hermit crab, C. Clypeatus, which is the species of hermit crab that is most often sold at as pets and usually has a purple pincer. Often, inexperienced people will mistake a purple pincer for a strawberry, because the purple pincer may have some red on it.

Pictures for Comparison:
C. Clypeatus (purple pincer)
C. Perlatus (strawberry)

There is much more care information at CrabStreetJournal. They are an extremely reputable hermit crab care forum, and they also have an adoption section.

How You Can Help

1 Don’t Purchase Hermit Crabs From Pet Stores, Boardwalk Shops, etc.

They are much better off in the wild instead of in captivity, where they’ll probably only live for less than a year, even if you know what you’re doing. Instead, look through your newspaper, Internet classified ads, etc. for an adoptable hermit crab. Some hermit crab websites also have adoption listings on their website.

Educate Others

Inform others of the responsibility of caring for hermit crabs and why they should not purchase them from pet stores. Hand out care sheets, create YouTube videos, or even send people IM messages to get the word out. There are many creative ways to get the message out that hermit crabs are not as easy to care for as businesses try to convince people.

Write to Hermit Crab-Selling Shops

If you know of a place that sells hermit crabs that does not care for them correctly, you can write them to correct them on what they are doing wrong. Try to mention how it will affect their profit, since they are a business and mostly just care about money. For example, if there are dead hermit crabs in the tank, try to convince them that people will not buy from stores with dead hermit crabs, because they may fear that there is something wrong with their hermit crabs.