What is molting?

I am a new hermit crab owner so please tell me...What is molting? Is that when the crab takes a new shell? How often do they molt. I have no extra shells. Do you know where I can order some on line or over the phone?

edited to add <span class="ev_code_GREEN">is molting</span> to the title. Since Moire_eel gave such a great explanation, I am moving a copy of this post to the library.

 

Molting is when a crab sheds its exoskeleton in order to grow. Sometimes you'll notice that the behavior of your crab changes as it prepares for a molt: drinking and eating a lot, digging, or seeming sort of sluggish. Different crabs prepare in different ways, it seems, so there's no guarantee you'll see any of this.

Most crabs will bury themselves to molt. When they dig under, they continue to wear their shell, since that's another way they can take extra water with them. Usually once a crab has dug under to molt, you won't see it again until it is finished. While it is buried, it will shed its exoskeleton (kind of like taking off a very tight shirt ). The crab will be soft at first, and very tired -- molting is a huge ordeal. Then its new exoskeleton will start to harden up. The crab eats its old exoskeleton as it recovers to regain the nutrients it contains. When it feels recovered, it will resurface and start behaving "normally" again.

That's a typical molting pattern, but few crabs are absolutely typical. Some won't give any pre-molt signs, some won't bury, and a few will shed their shells and molt naked. There are probably an infinite number of variations, which is why we all worry when our crabs are molting. Two crabs of the same size may take very different amounts of time to molt, and if the crab has a leg or claw to regrow, that changes things too.

Often crabs will go "shell shopping" either before or after a molt to find a bigger shell. If they can't find a new shell when they think they need one, they may try to take one that one of their tankmates is still wearing, which is a very bad scenario that could end in death for one or both crabs involved. So definitely get some shells! I reccomend http://www.naplesseashellcompany.com -- they have a section just for hermit crabs, and sell shells by opening size, so that you can get shells that fit, or with a little extra growing room (your crabs should have some of both available!) The rule of thumb is three extra shells per crab.

Other places I have ordered shells from include http://www.petdiscounters.com -- they have a section of their site just for hermit crab supplies. You can also check out http://www.seashellcity.com Some species of crabs tend to prefer particular types of shells. Do you know what kinds of crabs you have? If you're not sure and can post pictures, we can help you, and make some reccomendations. Good luck!