Sadness

I use one of those under tank heaters for my hermit crabitat. I put it on one side of the tank so that it has a temp gradient across it and the crabs can choose how warm they want to be. I also use the cocunut fiber (don't buy the little discs in the hermit crab stuff, they sell bricks of Eco Earth for like $4 that is the same exact thing). The coconut fiber needs to be at least a couple inches deep so the crabs can bury themselves. Also, get the sheets of cocunt fiber stuff to make ramps and such for them, they like to climb.

I've been keeping hermits for about a year now. As I said, I use the EcoEarth shredded coconut fiber as a substrate, about 2"-3" deep. It's very moist (comes in a hard, dry brick you soak to pull apart), I moisten it with a mild salt water rather than plain water because I read that helps deter any mold growth. I also use a 10 gallon tank for mine with a glass lid to keep it humid. I got a sheet of coconut fiber backing that I cut up and made ramps and hammocks with. Instead of using those pricey/pretty water bowls from the pet store, I got a pet dish that had two "bowls" in it and put a clean rock in each one so the crab could climb up on to get out. One side is salt, one is fresh. I keep the crabitat warm with an under tank pad heater for reptiles which also keeps the substrate warmed and thus humidifies the whole tank. Because the lid is glass, the humidity stays constant. I also hung some fake plant material from the shell changing hammock for decoration. I use a small ceramic bowl I had on hand for a food dish and a scallop shell half as a treat dish. My hermies climb and explore their area and if I can't find them, I know they are buried in the substrate sleeping. I'm not too sure on the lamp for them, they are more of a nocturnal creature which is why he was probably hiding from the lamp before. I made the hammock for a shell changing area because if the shells are on the substrate, they bury and fill the ones they don't like. Also, that special hermit crab sand they sell for outrageous money is a scam. Make sure you feed them a variety of real food, not just the pellets sold for them. They need beta carotene to keep their vivid colors. Mine love applesauce (treat dish) and carrot shreds, boiled egg whites. I'll see if I can attach a pic later. I don't spray my crabitat down with a misting bottle daily because as I said, the coconut fiber is very moist and the heat and glass lid all combine to keep it relatively humid in there.

Yes, mine hide most of the time. They bury themselves in the substrate and come out in the evening to explore and eat. They are more nocturnal creatures.

Aww man! Lol. (pics are up on my thread) I imagine he'll definitely burrow in sand.

Yeah, he will burrow in the sand. Some people like to do a half sand/half coconut fiber mix for substrate so the crabs can burrow and tunnel in it. They will also hide in little structures. Anywhere they will feel secure. The substrate needs to be deep enough for them to bury themselves in because they bury themselves to molt.

100% sand isn't the best, really.
it doesn't dry and release humidity. they breathe through modified gills that can dry up and thus they'll suffocate slowly if humidity is too low.
it doesn't suck up excess moisture. when they bury themselves to molt... if there's enough water in the tank to keep humidity up... there's a possibility they could get down so far and drown as the water comes in over them.
sand and coco-fiber mixed gives good properties for a soil... good drainage... good moisture retention... less compacting... etc. good for them for molting, too.

to help keep the humidity up... close the top in most of the way with a solid cover. (glass, acrylic, polycarbonate, etc.)

silk plants work great for cover if you can keep them stationary.
chola wood is a favored climbing apparatus typically.

if you construct a b/g such as the one mentioned above, keeping the humidity up should be simple.

cuttlebone may or may not be relished by your guys. if they need the calcium for molting it's probable they'll take to it, IME.

anyway... any decent hydroponics shop should have good coco-fiber for just a couple bucks a brick... gro-dan/coco garden/coco tek/etc. ... unlike the stuff you get at pet stores, you'll have a hard time finding one of these bricks where something just happens to grow spontaneously out of the soil once it's re-hydrated... and you certainly can't argue the price for what you get...