Hermit Crabs as Pets
Hermit crabs live in borrowed seashells.
When they get bigger, they move into a bigger shell.
There are lots of different kinds of hermit crabs.
Some live in the sea.
Some live on land and make good pets.
Hermit crabs are not closely related to true crabs. They got their name because they live in a cave-like shell, like the old hermits who lived in mountain caves. There are about 500 different kinds of hermit crab in the world. Some live in deep sea water, some in shallow coral reefs and beaches, and some are quite large. One kind that lives in the Caribbean islands climbs trees. In warm places there are many kinds of hermit crabs that are terrestrial, or land-living.
Most kinds of hermit crab have long soft abdomens, making them vulnerable to predators. They protect their abdomens by moving into and carrying around an empty seashell. The tip of the abdomen clasps strongly onto the centre of the spiral part of the shell. When the hermit crab grows too big for the borrowed shell, it has to move into a larger one.
Before you buy your hermit crabs, you must have a home ready for them.
Pet hermit crabs do not need huge homes, but the correct temperature and humidity is essential for their health and wellbeing. Terrestrial, or land, hermit crabs come from warm places so they need to be kept warm.
Glass or plastic fish tanks with lids can be adapted to make a home for hermit crabs. The lid helps keep the air inside warm and moist. If you have more than one or two hermit crabs, go for a larger tank rather than a small one because they are sociable and like to move around.
Make a thick layer of sand on the bottom of the tank, because hermit crabs like to burrow into it. The sort of sand that is in a sandpit is good, or you can buy aquarium sand. Do not use gravel or wood shavings.
Hermit crabs do best if the temperature is around 22-27ºC. If it is cooler than this for long periods of time, they can become ill. A special lamp can be used at one end of the tank so there is a warm zone and a cooler zone. Keep a thermometer in the tank.
Hermit crabs breathe through gills, so the air needs to be moist or they will suffocate. With warmth and a solid lid on the tank, the water dish should be enough to create humidity. It is also possible to put a sea sponge in a dish of filtered water for extra humidity.
However, you do not need too much humidity or fungus will grow inside the tank.
Pieces of driftwood or other wood, or coral, in the tank provides obstacles for the hermit crabs to climb on.
In the wild, hermit crabs are omnivores, which means they eat plants as well as meat. There are commercial dry foods available in pet shops for hermit crabs. Any uneaten food in the food dish should be removed each day.
In addition, feed your pets fresh foods including:
|papaya or pawpaw||coconut (fresh or dried)|
|leafy green lettuces (not iceberg lettuce)||
|freeze dried shrimp (from the fish food section at the pet shop)||leaves and strips of bark from deciduous trees (not conifers)||raw unsalted nuts|
|brine shrimp||fish food flakes|
Hermit crabs need calcium so cuttlebone (from the bird section of a pet shop) can be given whole or scraped and added to their food dish. You could also add crushed shell grit, also from the bird section, or crushed egg shells to the food dish.
Fresh water is needed for drinking. Use filtered water or rainwater so there is no chlorine in it. A larger dish of salt water can be provided for the hermit crabs to get into. Do not use table salt. Saltwater can be found in an aquarium shop that sells saltwater fish.
Shallow, strong and easy to clean dishes are used for food and water containers, and a larger one for saltwater.
This page was written for Year 1L and Mrs Leetham because they have new pet hermit crabs in their classroom!
Go here to find out more information about hermit crabs:
All the photographs on this page ©  Jupiterimages Corporation
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If you use any of this in your own work, acknowledge the source in your bibliography like this:
Sydenham, S. & Thomas, R. Hermit Crabs as Pets [online] www.kidcyber.com.au (2009)
updated July 2009 © kidcyber