i just got one.. small still and its been around my corals but not to much and i havent seen any thing eating them at all. IF she does get bi&%$y and start the buffet of my $700.00 worth of corals she is O U T that is OUT!!! already showed her the plan of action.. LONG PINCHING TONGS BABY SO BEHAVE!!!
im pretty sure there ok i havnt had problems. and my lfs has one in his show tank thats like 8-9inches big (with legs) and he has no problems. i will say they can knock unglued corals over. great for algea control