However, these starter kits are sadly lacking in what hermit crabs need for even basic survival--most hermit crabs who live in these conditions will die within their first few molts.
My family bought two hermit crabs on impulse during a trip to Galveston, TX. One died within weeks, and my dad went out and bought two more to keep the first company. Those two died, and for some reason, the first hermit crab hung on for nine years in the worst of conditions--tiny 5X10 inch plastic cage, colored gravel, a sponge, the same commercial food for nine years, and tap water in a small shell. The plastic cage sat on the floor of the family bathroom, and poor hermit crab probably only survived due to my mother's diligent weekly cleanings, and the humidity that came from us taking showers in the bathroom.
It wasn't until I was in my senior year of college that I took the hermit crab and slowly figured out how to properly take care of it. Hopefully, as hardy as this particular hermit crab is, it will live out its next 20 years in hermit crab luxury (as hermit crabs can live to be 30 years old or more).
So, the following is a how-to for building the perfect crabitat--the equivalent of a crab mansion!
1. Decide what type of container you want to house your crab/crabs in.
Most people like to be able to look in on their hermit crabs, so a glass or plastic aquarium is best for this purpose. The cheapest container, in my experience, is a 10 gallon glass aquarium that can be purchased at Wal-mart for about $10. (Cheaper than Petsmart or Petco!)
You can also use a tupperware storage container if you don't care about looking in on your hermit crab. But, be warned that it will be more difficult to keep tabs on the temperature and humidity gauges (which we will talk about shortly), and the general well-being of your crab, if your cage isn't clear. Also, you won't be able to enjoy your crab's environment, which can be very calming, if set up (landscaped, if you will) artfully.
2. You will also need some sort of cover for this container in order to keep the humidity at a level high enough for your crab--I use a screen cover made for aquariums, with plastic taped on the underside. Other choices are saran wrap, or glass covers made from aquariums.
3. Decide what sort of substrate you want to use. (This is the stuff that goes on the bottom of the cage)
Most places that sell hermit crabs with starter kits sell bags of colored aquarium gravel as the substrate. While this may be okay for part of the cage, crabs will also need an area where they can dig and tunnel into, in order to molt properly. This substrate can be prepared playsand or forest bedding.
4. Other necessities:
Temperature and Humidity Gauges
The target temperature for your crabitat should be between 72 and 80 degrees Fahrenheit while the target humidity should be around 72. Too dry, and the crab will dehydrate. Too wet, and the crab will suffocate.
Go here for suggestions on how to maintain good humidity.
Good brand for these gauges:
Two Water Containers
One for dechlorinated water, one for salty dechlorinated water. Tupperware works well for these purposes--just make sure to fill the containers with enough gravel so your hermit crab will be able to get out again if it decides to take a bath in them, which they sometimes like to do. Otherwise, they could drown.
Food Container and Food
Any container works, really, that they can get into and out of.
For hermit crab food, visit the Hermit Crab Addiction store (link on left navigation bar). This is where I buy my hermit crab food, and SuperCrab loves it. He used to not eat very much at all, when I only fed him the hermit crab food you can buy from Petsmart. Now, he eats like a little piglet. Strawberries are his favorite.
(that are slightly larger than the current one your hermit crab is using)
It is best to buy the more natural looking shells, as the paint on the painted shells can be toxic.