crabs reef safe or not? i have a red crab about half an inch big its red and green/blue dots on the back shell. not eating none of the corals. today a birdnest frag was gone found it in his cave cant take it out. just took the frag plug out. came back from work and looked in there and there was my pink birdnest frag in there. took it out. and close to it was my ora green birdnest frag. do they like sps? can some one help me please. and whats the best way i can get my frags out the cave? its a hole in a rock which travels through out the whole rock. all the way at the bottum also. please help identify this crab... cant snap a pic it comes out at like 4am only...