HCA: Hermit Crab Association

Why is it that some crabs roam the surface all the time while others insist on hiding under the substrate for days at a time? Out of 4 crabs, only 1 is out for me to see. The others hide all the time (1 molted and should be up any day now) and another is pending either a molt or death from PPS..not sure yet. I am too much of a novice to know the difference) but no matter what, these three always stay under while Whiskey is all over climbing and sleeping in the moss in her shower caddy soap dish. She always comes to see what new foods are out and I am tossing out food every day for the others (she is still in ISO)I want more crabs that I can see and enjoy!

Hi Critter Keeper. I know the problem. Set up this beautiful crabitat, put the hermies in that you so lovingly chose from the pet store, and all they do is disappear. This seems like a natural thing to do and is probably based on instinct and personality. Some species are shyer than others. Crabs like to dig and the time spent getting from the beach to your crabitat may have been shorter than most. It's hard to say. This is a natural thing for them to do. I have crabs in my 20 high that I believe I see once every two months. Enjoy your baby that is out doing visually crabby things. The others will be out in time. Just believe that they know what they're doing and be patient. God Bless.

Some do need a much longer destress than others due to prior circumstances. One of mine destressed for 2 months without a molt. Just needed that amount of time to get back on his feet.Jedi Master Thrash also made an observation not long ago that by limiting tank decor in our attempt to provide roaming roam we might be unintentionally driving them underground. Hermies love nooks and places to hide and tuck and I think there's a lot of truth to that.Finally it could be an issue of climate. Do you use overhead lighting? They could be going under to find or escape the heat. Do they come out at all?

Species can have a part in it as well. Es, which tend to live closer to the shoreline than PPs, have a tendency to bury more, especially during the day. PPs, which live more in mangrove swamps, head for the trees during the day. It makes total sense from an instinctual perspective. On beaches, where it's quite possibly more open, hiding underground from birds is probably safest. In the swamps, the best bet is probably high up. There's exceptions of course, and once in the tank, behaviors can change quite a lot I think, but I think that's why the wild differences.

Assuming you have enough surface hidey-spots, in a normal tank at any given time, about 1/3 of the crabs will be visible, 1/3 not buried but hidden, and 1/3 buried underground.With only 4 crabs, 1 is roughly 1/3rd So you're not necessary far from average.Increasing the heat and adding daytime UV lights helps bring the crabs out. If you're only using a UTH, sometimes they'll bury because the sand stays warm, but the surface and air is much cooler without lighting.Roughly 1/10 to 1/8th of my crabs at a given time will be in a position where they are clearly "basking" in a heat lamp.