Molting?!?!?!

Question
Hey LolaGranola!
Both crab's have been digging, I made a moist misted hole for them, put them in they crawled out. This morning I was missing one, I was in shock! Then I found him in a corner, I can see his shell sticking a bit out not all, just the top, he hasn't moved at all, or I don't think so the tank smells like sand, humidity sometimes go to 40% if I forget to mist, but I mist couple times till it's in it's 75-80% my temperature dropped before but then I turn on my light again and it'll warm it up, at night I have it off because we're scared it will cause smoke if it gets too hot and burn the crabs/ and our house! Anyways, It hasn't moved but I misted him incase he's molting, my other crab is starting to dig in a place without the big hill that I made and I made him a hole and put him in, he crawled out! The other places with sand aren't deep enough so I'm scared he'll surface molt. Though, when I got them both their colours were brighter, recently they have began to get duller just a little bit lighter. Any ideas if they want to molt and if the one that is under the sand molting? Remember I can see his shell still though but he's not moving, if they are molting how long will it take? They are medium not jumbo not too small, but a small medium.
--Thanks!

Answer
You need to have your substrate deep enough for them to bury in and then leave them to do their thing when they are ready. Molding can take up to 2 months even for a small crab. Just keep an eye on him and all should be well, it's so hard to wait isn't it?!