Hermit Crab Facts

Hermit Crab

Hermit crabs are fun little pets, but many think that they are ideal “starter” pets for children because they require no special care. While they can make good pets for children, hermit crabs DO require special care. Below are some hermit crab facts followed by some tips about the proper care of these fascinating creatures.

• A hermit crab can live for up to 15 years in nature. Such a long lifespan is very rare for hermit crabs in captivity. Many hermit crabs in captivity only live about one year.

• Hermit crabs are related to both lobsters and spiders

• There are 800 different types of hermit crab.

• Even though some hermit crabs are born in the water, they can still drown if forced to be underwater for too long.

• The gills of a hermit crab must be kept moist. If not, the gills will become dehydrated and the hermit crab will die.

• Hermit crabs pick the shells that will be their home, and many tend to gravitate toward a shell that has a mother of pearl lining.

• Hermit crabs are not really crabs. A true crab’s shell is part of his body. A hermit crab’s shell is simply housing for his body.

• In nature, hermit crabs live in colonies of many crabs – sometimes more than 100.

• Hermit crabs are subject to getting mites in much the same way that a dog or cat may be subject to getting fleas.

• It is extremely difficult to breed hermit crabs in captivity.

• Hermit crabs eat their shed skin after molting.

• You can cause the death of a hermit crab if you dig it up while it is molting or if you touch it shortly after it has shed the old skin.

Now that you have learned some fun and interesting hermit crab facts you can now take a look at some important things that you need to know about the proper care of pet hermit crabs.

Hermit Crab Care Tips

Choosing a Hermit Crab

Many hermit crab owners report that the hermit crab died shortly after they brought it home or that it exhibited signs of extreme distress, such as losing legs. (NOTE: dropping legs is NOT molting. If your hermit crab is dropping its legs it is usually a sign of stress.) While there is no way to ensure that you are bringing home a healthy hermit crab, there are some things to look for when choosing your pet.

• Do not choose a hermit crab that refuses to come out of its shell.

• Do not choose a hermit crab from a pet shop in which the tanks are dirty or have flies or other insects in them.

• Do not choose a hermit crab that has a musty odor. That is a sign of disease.

By choosing a hermit crab that is as healthy as possible, you will have a better chance of the pet becoming acclimated to and happy in his new home.

Hermit Crab Housing

As is the case with many types of pets, the housing is very important. When you buy a hermit crab from a pet shop, it often comes in a small plastic container. Some find that these containers are OK for use as an isolation tank (to be discussed below), but they are NOT adequate for housing.

Your hermit crab is going to spend his life in the tank. It must be large enough to keep his food and water bowls, a variety of toys and still allow room for the hermit crab to tunnel and roam around. A ten-gallon tank is a good place to start. The size of the tank that you will eventually need depends on the size of your hermit crabs and how many hermit crabs that you plan to keep in the tank.

The tank MUST be kept at a proper temperature and at a proper level of humidity. The temperature should be about 75° F with a humidity level of 70%. This requires the use of an under tank heater. One way to keep the tank humid enough is to place a sponge in a bowl of water and place the bowl over the opening for the heater. REMEMBER: a too cold or not humid enough tank will result in the death of your hermit crab.


The substrate is what you will use to line the bottom of the tank. Some choose sand; others choose a fiber specially made for use in hermit crab tanks. Many expert hermit crab keepers say that a combination of fiber and sand is the best choice.

• The sand for the hermit crab tank must be clean. While you can buy hermit crab sand at the pet shop, this is not necessary. Instead, you can opt for sandbox sand. Sandbox sand is just as clean as hermit crab sand and is a whole lot cheaper. Keep in mind that if the sand that you buy has a strong odor, you should not use it. Instead, return it to the store for a new bag.

• The fiber substrate should be something that was specifically made for use in a hermit crab tank. This is readily available at most pet shops.

The substrate will help the hermit crab warm up if he becomes a bit too chilly and will also provide a place to dig.


Hermit crabs are not too choosy when it comes to what they eat. They enjoy veggetables, fruit and even some meat. Some feed their hermit crab human food, but if you want to be sure that you are feeding your hermit crab a proper diet, the best option is to choose a high quality hermit crab food. You can then offer occasional treats of fruits, vegetables and meat.

The water bowl in your hermit crab tank will be used not only for drinking, but your hermit crab is likely to take a dip in the bowl from time to time. For this reason, you must make sure that the bowl is not too deep. If the bowl is too deep, the hermit crab can drown. One solution is to place a sponge in the water bowl. This will allow the hermit crab to be in the water bowl without being in danger of drowning.

Chlorine is very harmful to hermit crabs. THE WATER THAT YOU GIVE TO YOUR HERMIT CRABS MUST BE DECHLORINATED. You can buy water dechlorinator at most pet stores. Treat the water according to the directions on the package. You should clean the water bowl and add fresh water daily.


A hermit crab is not really a hermit. In fact, hermit crabs need friends in order to truly be happy. It is best to keep at least two hermit crabs in your tanks, but even more is better.


Do you need to bathe your hermit crab? Probably not. Is it harmful? Not if you bathe the hermit crab properly. All you need to do is dip the crab into water and then allow the water to run out of the shell. Repeat until the water running out of the shell is clean.

If you are treating for mites, bathe the hermit crab in order to get the mites off of the crab. You will generally need to dip the hermit crab two or three times to accomplish this.


One of the most interesting things about hermit crabs is the molting process. This is when they shed their skin and grow new skin. The entire molting process can take about a month. Here are some things you need to know.

• Learn to spot the signs of molting. This includes a hermit crab that stays under the sand more than normal and that is not very interested in eating or drinking.

• If you think that your hermit crab is about to start molting, move him to an isolation tank.

• Once in the isolation tank, see if the hermit crab stays under the substrate. Gently slide the sand away from the hermit crab. If he does not move, gently cover him again. If he does come out and starts moving around it is likely that he is not molting and can be moved back to the main tank.

• Once the hermit crab emerges, has eaten some of the shed skin and is moving about the tank, he is ready to leave the isolation tank.

• Most adult hermit crabs go through the molting process about every 18 months.

• Do not touch a molting crab.

Isolation Tank

The isolation tank can be much smaller than the main tank. It should be used for quarantine when introducing new hermit crabs, for molting hermit crabs or when you think one of your hermit crabs has a disease.

You will still need to keep the temperature and humidity at desired levels and provide a food and water bowl.

Hermit Crab Toys

Some are surprised to learn that hermit crabs love toys. These creatures enjoy hiding and climbing so provide plastic plants, driftwood, tubes and other toys that will allow this. Rearrange the toys in the tank from time to time to give your hermit crab “new” places to explore.

Hermit crabs are wonderful pets, but you must take the time to learn about their needs and to provide the proper environment so that they can live healthy, happy lives.