HCA: Hermit Crab Association

I had life last night in one of my tanks, Unicorn has come up but he did not molt. He was moving around and what not. I scared him and he tumbled over in his shell and it looked like there was a bug on him. I took him out to get a closer look in the light and he had a smell. Not a fishy smell at all, not a tank smell. By the way the black thing I thought was a bug was a piece of moss. So my question is, do crabs have a smell? I have never noticed this smell before either. Could it be he picked up a smell from the sand from being buried?

What kind of smell? A musty smell? If so, I had a musty smell for a bit in my
tank and it was because of poor circulation; an easy fix.

yes the chemicals they use to molt smells very weird. Almost like rotten medicine, and it goes away as they dig. You can give him a little bath if you really want but you don't have too.

Do they have the smell even if he did not molt?

I'm not sure. He may have some food back in his shell that stinks or something. Can you find out if your substrate smells like he does in any areas? Maybe he's just getting a smell from the tank somewhere. Maybe a moss pit has some rotten stuff in it.

OK, did some investigating. He bathed himself in both salt and fresh water because there is sand at the bottom. I scooped some sand and sniffed it(which got some weird looks from my daughter) and it didn't smell like him, neither did the moss pit. I smelled him again and he doesn't smell. So whatever it was he washed it off in the water.

if it's a "old leather boot" smell it could mean bacteria got into his shell. keep checking him. as a habit i recommend sniffing your crabs once a week unless they are in molting, you usually can tell if something is odd. otherwise they really shouldn't smell at all, other than when they get covered in their own food

Jackolope, wasn't old leather boot smell. I am thinking it might be a molting smell because he had a molt sack. I will sniff him in a couple days. Although I have this vision of smelling crabs and them pinching my nose with their big pincher!

if he has a molt sack then leave him be, he probably is molting and any smell should be gone once it's over. mine never pinched me for sniffing them LOL

To me, the molting smell is like ladybugs or fireflies. A medicinal iodine like smell.

I've had them smell before, but it was an odd indescribable smell. Not unpleasant, not pleasant, just.... odd. Never figured out why.

I have not smelled him since but he has dug down a little. Tip of his shell is sticking out so I will leave him be. Wode, it wasn't pleasant or unpleasant.

Sometimes they go down for a while to chill before molting, and come back up to eat and drink and roll in the saltwater right before molting. I'm guessing he is going down to molt now, yay!