What Is A Hermit Crab: Everything You Would Want To Know

What is a hermit crab?

Hermit crabs are crustaceans and are part of the arthropod family. That means they have an exoskeleton, a hard external surface that protects their organs and muscles, but hermit crabs don’t have a completely hard exoskeleton, they have a soft abdomen, which must be protected.

In the case of hermit crabs, they use the shells of dead snails and other shellless animals that they find in their environment and that fit their size.

Hermit crabs are closely related to crabs, lobsters, crayfish, and prawns. Some live all their lives under the sea, but many live at the edge of the sea, so they are ideal for aquariums with a sandy and humid environment. Some land hermit crabs live entirely on land.

As Hermit Crabs grow, they outgrow the shell they are living and have to find a new one. In places where shells are scarce, crabs may actually find a shell they like but there is a crab already in it. It has been known for crabs to gang up on a crab with a shell they want to force the crab out.

Sometimes crabs form a kind of a train, where the crab with the largest shell leaves to take a new one, then one by one the crabs get out of their shell and into the next one that is a little bit bigger.

Hermit Crabs though hermit by name, are actually social animals and like to be in groups. It is good to have 3 or 4 crabs in an aquarium.

Of the approximately 15 terrestrial species in the world, most commonly Caribbean hermit crab, Australian land hermit crab, and the Ecuadorian hermit crab are kept as pets. Hermit Crabs are generally omnivores which means that they eat both meat and plants.

They are scavengers finding dead animals or plants to feed on, which is good for aquariums because they like scraps from the dinner table. Vegetables and meats are fine but not processed or refined foods.

Land vs Aquatic Hermit Crabs

To clarify from the beginning there are two broad categories of hermit crabs: land and aquatic. As the name implies, land crabs live on land and aquatic crabs live completely underwater.

You will certainly see aquatic hermit crabs in marine saltwater aquariums, but all hermit crabs that are sold exclusively as pets.

Land hermit crabs, like their underwater cousins, are related to shrimp and lobsters. They are popular pets kept by enthusiasts in glass aquariums called “crabitats” and are available in most pet stores.

No matter how physically small they are or how little maintenance they may be, hermit crabs are still living creatures with specific needs that must be met. For that reason, it is imperative that you understand these unique animals to properly care for them.

Types Of Hermit Crabs

There are 1100 different types of hermit crabs in the world but only half a dozen types of hermit crabs are generally kept as pets, and within that group, there are only two that you will find readily available in pet stores: the Purple Pincher and the Ecuadorian.

Purple Pinchers Hermit Crab

The Purple Pincher hermit crab is also called the Caribbean hermit crab, soldier crab, West Atlantic crab or the tree crab that you will see most often as a companion animal.

Actually, they are very beautiful creatures, with multiple colors on their legs in a range of shades that include red, orange, yellow, purple and tan.

The front pinchers or “claws”, especially the left one, which is generally larger, is almost always purple, hence the name. They have long, slender eyestalks, and point-shaped eyes. The Purple Pincher is a little less active than the other commonly maintained species, the Ecuadorian hermit crab, but they are more willing to use their claws if they are afraid.

The scientific name of the species is Coenobita clypeatus. They are indigenous to the Greater Caribbean, but they are also found in the Florida Keys, the Virgin Islands, the West Indies, and Venezuela.
Individual Purple Pinchers generally sell for around $9- $10 / £5.51 £6.13 each.

Ecuadorian Hermit Crab

Ecuadorian hermit crabs are one of the smallest species of hermits with an average size of only 0.47 inches or 12 millimeters.
Its scientific name is Coenobita compressus. In most cases, this species exhibits a tanned body, but they can be bright yellow, orange or dark gray. Occasionally, individuals will have a blue color to green tint on their bodies or inside the legs.

The eyestalks of the Ecuadorian are similar to that of the Purple Pincher, but its eyes are shaped like commas. They have a particular preference for shells with round, wide openings.

They are fast, active, and excellent runners, rapidly switching gears to move forward, backward, and sideways without ever slowing down.

They are also the species that are most active during the daylight hours, which is one of the principal reasons they are attractive in the pet trade. Do not even think about keeping an Ecuadorian Hermit without giving him lots of things to climb on.

As a result, you have to be careful about escapes with this species as there have been reports of them climbing the sealant in the corners of glass aquariums.

Typically, individuals are priced at around $7-$8 / £4.28-£4.90 each.

Other Types Of Hermit Crabs

There are four other types of hermit crabs that do show up in the pet trade.

Not all are commonly available, but you will see:

  • Indonesian Purple Hermit Crab (Coenobita brevimanus), the largest of the hermit crabs, and the one considered to be the most mellow and relaxed.
  • Cavipes (Coenobita cavipes), a shy crab prized for its appearance. A cavipes’ body is black, blue or red, and its antennae are also red.
  • Rugs or Ruggies (Coenobita rugosus) is also called the “crying” hermit crab for the unusual sounds it makes when it’s upset. It comes in all shades including bright red, peach, chocolate, blue, brown, and white.
  • Red or Strawberry Hermit Crab (Coenobita prelates) is a rare, bright orange-red crab with distinct white bumps on its legs and claws.

You will have a great deal of difficulty finding any of these hermit crabs in pet stores, although they are becoming more readily available from expert breeders.

All six of these popular species require the same type of care, however, so there’s no need to learn specific husbandry standards for each one.

How Long Does a Hermit Crab Live?

I want to very quickly dispel the notion that hermit crabs are short-term pets. If cared for properly, hermies can easily live a decade. Don’t make the mistake of thinking you are getting hermit crabs for children as “short-term pets.” You’ll only wind up caring for the crabs when your son or daughter goes off to college. In short, they live up to 20 years.

Hermit Crabs And Children

With the proper amount of adult supervision, children can do most of the work to care for hermit crabs on their own, but it’s a good idea to make a checklist of daily chores. As the parent, you need to ensure that these tasks are actually performed, especially where humidity and temperature levels are concerned.

Also, make sure that your child washes his or her hands before and after handling the crabs. Since younger children are not consistent in their hygiene habits, this is a protection for all concerned.

Children must understand that hermit crabs are living creatures, not toys. If a hermit crab is dropped from even a short height onto a hard floor, the impact can be fatal.

Hermies are susceptible to many kinds of stress. They need to rest during the day, and they don’t like to be poked and jostled around all the time. They won’t do well in high levels of noise or with a lot of harassment.

All children must be taught to treat animals of any species gently and with kindness. Hermit crabs certainly cannot harm anyone or anything, but they can suffer great injury to themselves, and will die quickly if they do not receive appropriate care.

Hermit Crabs And Other Pets

It is generally a mistake to assume that other pets in the home will completely ignore the presence of a tank of hermit crabs. Dogs may represent a lesser danger, but a cat will certainly be intrigued by the crabs and will try to get into the crabitat.

If you bring hermit crabs into a home with existing pets, make sure that you have a secure lid on the crabitat that cannot be pried off. Keep the tank up high, and eliminate avenues of access.

How Many Hermit Crabs Should You Keep?

Never try to keep just one hermit crab. These creatures are very social and are much, much happier living in groups. Crabs that are housed alone become highly stressed and will eventually fall ill and die. Two crabs are good, but three or more are better.

Pros And Cons Of Hermit Crabs

Frankly, it’s never easy to put together a list of pros and cons for any pet. Some people think taking a dog for a walk every day sounds like absolute heaven, while others cringe at the idea and prefer a nice indoor cat with a litter box.

Hermit crabs are, by definition, exotic pets. For that reason alone, you need to be absolutely sure you’re doing the right thing before you bring hermies home. And do note that I used the plural. Hermit crabs need company. You will need to keep more than one.

With these ideas in mind, interpret each of the following points for yourself and decide if they are positives or negatives in regard to keeping hermit crabs as companion animals.

Hermit Crabs Are Quiet

I do have to add a disclaimer here. While hermit crabs won’t bark and keep the neighbors awake, they are very busy at night and love to rearrange things in their crabitat. If you put them in the bedroom, you may be surprised at just how much noise they can make at night.

Hermit Crabs Don’t Take Up A Lot Of Space

It is true that in relation to other, larger animals, hermit crabs have minimal space requirements. You will, however, need to have the right location for the crabitat. It must be out of direct sunlight and in a spot where you can maintain the correct temperature and humidity.

Hermit Crabs Don’t Trigger Allergies

The hypoallergenic aspect of keeping hermit crabs as pets really is not subject to much interpretation. If you sneeze and have an adverse reaction to small mammals including dogs, cats, and rabbits, you won’t face the same struggle with a tank full of hermit crabs.

Hermit Crabs Are Clean And Do Not Smell

Again, the cleanliness aspect of hermit crab care is a hard point to see in any but a positive light. They are not difficult to care for, and with minimal maintenance, they will be quite happy in their crabitat for years. 

Hermit Crabs Are Inexpensive

As compared to a pedigree dog or cat, hermit crabs are downright cheap. You will, however, have a number of things to buy in the beginning, but after those first set-up costs, you won’t be taking your crabs to the veterinarian, getting the shots, or having to pay for a license tag.

Hermit Crabs Don’t Outgrow Their Habitats

I can truthfully say that hermit crabs are some of the most contented pets you could ask for. They do perfectly well in a glass aquarium for years, and they don’t outgrow their initial space.