I have a 15g tank with a pair of Fiddlers and 4 Mollies. the Fiddlers have been under water all day. there is a large rock formation to climb up, the top is dry. as well as a large floating turtle dock on the top for them to have land. there is a bamboo plant for them to climb up to get to the top.

they are eating, and the male is being fresh to the fish. but they have yet to come up to dry land. does it sometime take a while for them to acclimate and come up? if it like them with food... they will find it when they want it?

I have a red claw crab and it took him a few days before I noticed him come out of the water. When they need air, they will find anyway they can to get to it, so I wouldn't worry too much. They are just getting used to their new home.