I would say offer some food to it. My brittles will NOT come off the rocks for anything (the serpents come down when food hits the water). Ibreak up a piece or 2 of shrimp pellet and put it near them (move slow or they'll run off). They can "sense" it is there. If the star is hungry, it will wrap it up in a curly leg (you'll know it when you see it). If it is not really hungry, it will grab on and move it towards the disc and the food will just sit there and wait...until a crab takes it away or something. Good luck, I've lost a brittle and it's not fun !!!