HCA: Hermit Crab Association

This is going to sound nuts, but I swear its true. I've been observing her since I first noticed this, and its been a very steady pattern with very little fluctuations.
My crab, Pinky, is well known to be a notorious shell-swapper, but I started to notice a trend
Sunday-Monday shell:



Tuesday shell:



Wednesday seems to be random shell day following no pattern.
Thursday shell:



Friday-Saturday shell:

This is so weird, I did a test, come tuesday I took out her beloved polka-dot shell and waited until her usual time to come out (another pattern, always about an hour after lights out) And when she came out she went straight for the shell shop. I was amazed at this behaviour and even more amazed at her reaction when she couldn't find it. She started throwing shells out of the shell shop! Poor Cheeto was on the bottom level and almost got conked by a falling shell. She seemed really upset, so I put the shell in front of her and she hopped right into it. I tried to do this test again, but she only ran around frantically until I put the shell in the second and third time. Do you think she could have some sort of disorder? Or that her brains out of whack?

I have no clue but I think this is hilarious and adorable. Maybe she is just quirkey? Or maybe she likes all of them. What would happen if another crab took one of those shells?

Maybe its like undies with the days of the week written on them? Hahahahahhaha

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Tamara wrote:I have no clue but I think this is hilarious and adorable. Maybe she is just quirkey? Or maybe she likes all of them. What would happen if another crab took one of those shells?

The only crab I have thats about her size is Draco, they're the biggest crabs in that tank by a long shot. I only saw him checking out her green striped shell once, and she ran over and batted him with her claw! I forgot to mention, she also does everything at the same time. Her routine is: Come up an hour after lights out, run up to the shell shop, switch (or just play around if its still saturday) down to the moss pit, she plays (or eats) some moss, down to the bottom level, eats some dinner (by this time Draco is usually up and hot on her tail) Then a quick dip in the saltwater and a swim in the freshwater. Or sometimes she just sits in the freshwater for awhile. Then she likes to crawl on the vines and plants and run around in the running area. Then shes usually back underground 4 hours after coming up, yes, I stayed up all night and observed her a few times

I think that is hilarious!! I think she is brilliant!!! You are lucky to have such a character.

She definitely likes her routine! Adorable!

That's not "nuts" at all. Captive animals will often develop ritualized behaviors; sometimes these can be harmful or even self-injurious (head-banging, hair pulling to the point of creating bleeding sores, over-grooming in captive birds, etc.). It stems from having limited behavioral options and far less stimulation than they would have if they were still in their natural environment. It sounds like you have an enriched enough environment that you are providing your crabs with a variety of things to do, thus hopefully minimizing unhealthy rituals and encouraging as much as possible a pattern of behaviors that includes as full as possible all of their natural behavioral repertoire, which is what all good zoos now strive to provide. Since they are still living in an environment that is far more tightly controlled than a completely natural environment, where random events occur regularly and there is much more interaction with many different animals (thus a great deal more stimulation), it shouldn't be surprising if they fall into a kind of routine. It sounds like a healthy one, anyway. Occasionally changing things around in the tank is probably a good idea to keep them all behaviorally stimulated, but it does sound as if removing her preferred shells is stressful to her, so I wouldn't keep doing that.

(P.S.--Sorry if I sounded all "scholarish" there for a minute; I did my comprehensive qualifying thesis on behavioral consequences of captivity in zoo animals, so I tend to channel the standard "academic journal article" voice for that kind of info. :roll: )

I saw your other post about the "lovebirds" and was going to say she just wants to stay stylish and change things up for her man

Soulonely, I was thinking that! Little Draco is completely smitten she was running around in circles last night and he just sat and watched her, and then started following her! They're so darn cute, I'll be heartbroken if she has eggs because if SojMad and Wolfnipplechips can't get the babies to live with years of experience under their belt, I doubt I'll be able to
Dragon, its totally ok to be scholar-ish, I'm going for a P.h.D. in zoology, I love hearing your little lectures (in a good way!)
I try to keep her stimulated, to a certain degree, moving the moss pit and moving the shell shop or putting the food bowl anywhere else seems to put her into one of her fits, but I try to move everything else around. Its funny to see her sit and stare at the moved cholla wood, as if she wants it back in its old spot, and then slowly climb up it anyways
I just got a very big order from wodesorel (Draco is wearing one of her shells) So theres quite a few new shells in the tank. But nope, last night I saw her make the plod up to the shell shop and change into her Sunday-Monday shell :roll: Without even touching all the new shells in the shop or covering the ground. My poor, insane Pinky I love her to pieces.

SoulLonely wrote:I saw your other post about the "lovebirds" and was going to say she just wants to stay stylish and change things up for her man

When I read this, I wanted a "like" button!!

Remember that in the wild she wouldn't have these options - she could take the shell she sees right now and that may be the only shell she gets for the next two years. I think their constant changing is probably induced by us giving them so many options. Have you ever gone shopping in the sale racks and found three pairs of perfect shoes but could only afford to take one? How long does it take to make that choice and how many times will you second guess yourself and go back? And you know that if you were to come back later there's a good chance those other two pairs won't be there.

Because of this I would argue that it's not OCD. Crabs are naturally creatures of habit - they come out the same time every night, and they have the same urges from day to day. It's a bit odd that she likes the same shells, but I don't think it's too weird. Those are the ones that fit the best and none are better or worse than the others, so she can't decide which is better. And since they aren't being snatched up by another crab she's having days and weeks to languish over the decision.

Giggles used to change shells three times a day, every day, for nearly six months! And then he molted and got too large to fit comfortably in those shells and settled on one that was bigger and better. He's since changed shells maybe four times in the last two years. Maybe because I have a crab who went through it I don't find it too strange, but I really don't think it's a sign that something is wrong.

Wow, this thread really made me smile. This sounds soooo cute!

one of my PPs went 5 months or so with the same shell he came in. Now its a new shell every few days. his old shell was quickly snatched up, must be an ultra comforty shell.

I just wanted to update everyone quickly
Thank you all for your replies! I set up the new tank yesterday, with a much more stimulating environment, and twice as much room. Although she panicked at first, she has settled in beautifully, and almost completely tossed her repetitive habits. She has also broken the shell cycle! She is now enjoying Draco's comfy used shell, and he changed into one of her old ones ( )

that is cute of your crab to do that. My one crab won't make up its mind on a shell. It's been in 5 different shells since I had bought it of last week. I think I'm going to name him Swtchie. lol