Sally Lightfoot crab

[dlh]

I got a Sally Lightfoot a month ago.When I first introduced it to the tank it quickly found a space in between 2 rocks and has not ventured out since then! It ate all the algae in this space, and I fed it raw shrimp 3 times. I can see it clearly, but I wish it would eat algae off all of the rock work. Is this normal behavior?

 

[CHSUB]

What is normal for a crab? Haha. Ime, sally crabs are shy when small, however when they get big they are a menace.