Keeping Hermit or Crazy Crabs® as Pets
Land hermit crabs (otherwise known as Crazy Crabs®) are one of the easiest and most popular pets for children because they are friendly, odour-free and very clean. After setting up their new ‘crabarium’, kids will delight in listening to them scurry around at night and chat with each other about the day’s events.
Hermit crabs are not aggressive and can be handled on an outstretched palm easily but it’s wise to avoid the large grasping claw which is used for defense and for holding and climbing. Like most creatures, they respond to gentle care and learn to trust their keeper so they should be handled gently every day. It is known that some crabs have lived for up to 15 years as pets if they are well cared for.
This isn’t a case of “hermit by name, hermit by nature”. These crabs actually thrive in the company of other crabs and are more active when they have some mates to hang out with.
An aquarium with a glass top creates the humid environment that hermit crabs need and a 35cm tank will house three crabs. It’s important not to overcrowd them as this may cause them to fight with each other.
Small plastic tanks with handles are available but these are suitable only for carrying hermit crabs to school or friends’ houses.
The floor of the aquarium should be kept dry and covered with about 5cm of clean gravel or sanitized sand to mimic the beach on which they would normally live. Include a piece of driftwood, coral, or mangrove root for the hermit crab to climb over and a damp sea sponge for moisture.
The tank needs to be thoroughly cleaned every month or so. The gravel or sand, as well as the toys, should be changed or washed in salt water and allowed to dry in the sun and the inside of the tank can be wiped down with vinegar. Any wood ornaments can be microwaved for about two minutes but put a cup of water in at the same time for moisture. It is also a good idea to bathe the hermit crabs every week in lukewarm water with one or two drops of Stress Coat as this helps to kill any bacteria that might be hiding in the shells. Remember though that these are land crabs and shouldn’t be lowered into water for more than a few seconds as they will drown.
Hermit crabs are nocturnal and will often sleep for most of the day but at night when they are most active, they can be heard ‘talking’ to each other and scurrying around their tank.
HEATING AND HUMIDITY
Hermit crabs are tropical so they require high humidity and a temperature between 25°C and 32°C. The use of a heating mat under the aquarium is the best way to regulate the temperature and ensuring that there is always water in their drinking bowl will provide the humid environment that they require. Place a thermometer in the tank to help monitor the temperature but always make sure that it doesn’t fall below 20°C. Misting the crabs and their tank with de-chlorinated water every day will help create a humid environment as well.
FOOD & WATER
Specially formulated hermit crab pellets are available which contain all the vitamins and minerals that they need but they can also have an occasional treat such as a sultana, nuts, zucchini, apple, and other fruit. A piece of cuttlefish is great for the hermit crab to chew on as well but they eat very little so all uneaten food should be removed daily.
Two shallow bowls of water must always be available for hermit crabs. One bowl should contain fresh water for drinking that has been de-chlorinated with a water conditioner and the other should contain saltwater for bathing made from marine salt and de-chlorinated water. Use heavy, non-metal bowls so that they won’t tip over as the crabs climb onto them and place a sea sponge in the water so that they can get back out again. Clean the bowls thoroughly each week but without using detergents.
Hermit crabs live in the discarded shells of other creatures. As they grow they leave their old shell and find another to call home. Always leave a few spare shells in the tanks for them to move in to but ensure that they are only about a 1/3 larger than the old one. Don’t try forcing a crab out of its shell as it will only change houses when it is ready to. Sterilize the shells first by boiling them before being placed in the tank for your crab.
Better Pets and Gardens has a great range of painted and ‘designer’ shells available to provide your hermit crab with a bit of colour and personality. Or, buy a plain one and paint your own.
As they grow, hermit crabs will cast off their outer skeleton leaving them soft and vulnerable. Once this has happened they need to be moved to an isolation tank with sand, water, and food for a week or so. They will bury themselves in the sand while their skin hardens and although they will be mostly inactive, they will come out at night to feed. Take care not to touch them too much whilst they are molting and don’t remove the old exoskeleton from the tank as they will eat this later for its’ rich source of calcium.
Many crabs fall victim to poisoning without their owners realising it. Cleaning chemicals such as furniture polish, insect sprays, and air fresheners as well as hair sprays and deodorants can kill hermit crabs if they get into the food and water bowls. Even placing crabs onto carpet can kill a crab as they pick at the particles on the fibres which often contain detergents and oils. Lino and tiles that are cleaned and rinsed with no residue are much safer options.