six spot sleeper gobys!

[EdsonFOWLR]

Does anyone keep these guys, and is there anything I should watch for? Also got one on Saturday and up till last night it was diging a burrow under a piece of rock and coming out to eat frozen Mysis, but this morning I haven't see him resting just inside the entrance of his hole and I didn't see him come out when I fed the tank frozen brine and Mysis, should I be concerned?