HCA: Hermit Crab Association

Alright, thank you all, this is really helpful!

So, lately I've been having a few problems with my crabitat set up. First one is, My crabs have been escaping! I have a fish tank lid with the built in like and everything, but it had a few sections missing (where fish tank attachments and stuff would go). and they were getting out, so i switched to...

I have a 30G tank and i just made one (no sponges) and it has so far not helped at all. hasent been running long, but i dont see any improvement in humidity whatsoever. Suggestions? thanks!