HCA: Hermit Crab Association

Do hermit crabs ever molt in moss pits or do they always bury in the substrate? Just curious because I have one hermit crab that never comes out of the moss pit. She's super shy, but I was just wondering if she could be molting in there? I don't want to bother her if so, but want to make sure she's ok!!

I've heard of smaller crabs molting in moss pits because they are small and able to get the process done quicker, which means less threat of being disturbed. Mostly though, they belong in the substrate.