Discovery Academy: December 2009

While on vacation back in September, we brought home 9 new pets: hermit crabs. I have been interested in them for a while, but never really got down to studying them. When we saw them in Florida, we decided to get a couple. Actually, my daughter bought them. She picked out two; one for her and one for her brother. They came with a tiny clear box and some food and other things that are must have for crabs. We took them "home" with us that night and decided that we needed more. So the next day we went back and purchased 7 more for a grand total of nine. They are interesting. They are not rambunctious like a dog or even like my lazy fat cat, but they are way cool. Since we brought them home I have learned that several people have hermit crabs, but have no idea how to really care for them. So, I have decided to finally post about my hermit crabs.

This is our crabitat. It isn't as big as I would like, but it will do until I can find a taller one. I would really love to have one that was taller so I could build different levels for them to climb around on. They are excellent climbers. In fact, they are called tree crabs because they can climb trees. They can do this because of their two pinchers. One is very large in comparison to the other. It is used to hold on to things. If you are holding a crab, and it feels like it is going to fall, you could get pinched as it tries to hold on to your hand. We had this happen the first day we got our biggest crab. He was a frightening crab after that for a while. However, now we realize he is really docile and hasn't pinched since. We know how to hold them so they don't feel like they are falling.

Here is our biggest crab. We call him Big Green for obvious reasons. Yes, I know he is in a painted shell. He came to us that way. We didn't know any better; however, he hasn't found a shell he likes better. For those who may not know. Painted shells are awful. The process of getting a crab out of a natural shell and getting it into a painted shell so it will sell is akin to ripping you out of your comfy bed at night and sticking you in a motel somewhere. Actually, it is worse. It must be traumatic for these little guys. Also paint can chip off and crabs will eat it. They eat anything. Paint is toxic to crabs. Most of ours were in painted shell, but many of them have chose new natural shells.

Look at the size of that claw! Yes, he is is Purple Pincher. He (or she) is sweet, though. I am still the only one who will hold him. He is still scared of us. I hope with a little attention and some love, he will get over that some day. He has lived many years and who knows what all he has lived through. He must be a tough one.

Here is a comparison of Big Green and Pinkie. She is much small than her shell. In fact, just last week she traded to a much smaller shell and it fit quite well. She must not have felt comfortable, though, because she switched back after a few days. We have two other small crabs. One just came up from a molt and the other is down for a molt right now. The rest are a size between big green and pinkie.
Did I mention molting? Yes, they molt. They are Arthropods and Crustaceans which means they have an exoskeleton. In order to grow bigger they must grow a new skeleton and shed the old. We have had two do this so far and two are down right now. This is a very cool process. First, the crab will spend some time in the drinking water dish. He needs to drink lots of water. Our Big Purple (almost as big as Big Green) did this just the other night. He just sat in the water forever. The next morning I couldn't find him. He was down for a molt. They molt underground. They dig a hole in the sand and live in it until they are finished. The first of ours to molt didn't dig very deep. In fact, he really didn't dig at all. I figured he was molting, but I wasn't sure. He didn't move at all, that we could see. After a week of not moving, I picked him up. His claws and legs seemed a bit floppy to me. When I turned him over, they fell out. Oh my, was my intitial thought. Then I figured out he had molted. I looked into the shell and, sure enough, he was in there.

This is what he looked like. He was smaller than before. That seems strange, but he will swell to a larger size soon. That is what all that water drinking was about.

This is what fell out. There is no crab attached to these legs and claws. I carefully put the molted exoskeleton back into the hole and put the crab (Giraffey, we call him) on top. Crabs eat their exoskeleton (as do most creatures that molt) to get the nutrients they contain. Giraffey ate all except the big claw and maybe a leg part. Here he is shortly after his molt.

Crabs can be down for a molt for a long time. Giraffey did it in about two weeks. Another smaller crab took at least 3 weeks.

I figure Big Purple will be down for at least a month or longer because he is so big. You should be sure to provide lots of sand for your crab to dig in. The should be able to completely bury up. I have my sand angled with one end deep and the other shallow. It is deep enough for my biggest crab to bury up in. Also, you should never dig up a crab that is molting. It is trauatic and could kill them. Some people may think their crab is dead, but if it doesn't smell like a dead fish, it is still alive.

Can you see the hole in the sand? This is Big Purple. He has dug down to the bottom of the tank. We can check on him from time to time this way.

Here is another crab we call Walker. He loves to walk. He has changed shells also.

You may be wondering what that black thing is under my tank. This is an under tank heater. Crabs require warm temps of 72 degrees at least. Lower temperatures can kill them over time. Our house temperature is lower than that at night, so we need the heater. The heater heats the sand and the crabs sit on the warm sand. If the get too warm they can move farther away. Problem solved. I also put a heating lamp in the tank from time to time. The also need proper humidity to breathe. The breathe through modified gills that must be kept moist. The humidity level must be around 70%. There are several ways to do this. One way is to make sure your sand is always moist, at least the bottom 3/4 of it. Always keep two water dishes in the tank. One must be dechlorinated water for them to drink. You can decontaminate it using the same stuff you would use in a fish tank to remove chlorine and other toxic elements. The other water should be salt water. Do not use table salt. It is toxic. Use aquarium salt for salt water tanks. I use two old milk jugs to store my water. One has salt water and the other has dechlorinated water. You can also keep a spray bottle filled with dechlorinated water handy. I mist the tank from time to time. I usually mist the log because I know it will hold the moisture in for longer. Always keep a lid on the tank with a large hole for fresh air. This will keep the moisture in also.

I have had the question, "What do you feed them?" alot lately. Most folks just give them the crab food that came with them. That is all well and good, but crabs prefer a varied diet. They like something new each night. That is how it would be in the wild. They would just eat what they found. I use my crab food as my staple back up when I am tired and have nothing else to give them. They are omnivores, so they eat anything. Mine love peanut butter on a cracker and almost rotten banana. I have given them soup beans, ham, tuna, veggies and more. Just don't give them the stuff we aren't supposed to eat, like processed food or sweets. They shouldn't have much dairy either. They eat so little that it is sometimes impossible to tell if they ate any at all. Even with nine, I sometimes wonder if they even touched what I put in the tank. That is ok. They are small creatures. I love to watch them feed. There are tons of websites out there to help you care for you hermit crab. One of my favorites is: http://hermit-crabs.com/care.html
You can also Google crabitats and see what others are doing in their tanks. Youtube has some great videos of crabs changing shells.

I love my hermit crabs. They really do make great pets. They aren't self maintaining, but they are close.