Those bugs I also have, I think it may be bristle worms or snake tail starfish, but there are these creatures means that your live stone quality is good, if there is no big problem, do not worry about it. When you raise the water to take out the stone, when you rinse with seawater by the way with tweezers to catch out one by one. If it's really hard, you can refer to the answer upstairs or soak it in fresh water, but in that case just buy the dead rock and forget about it, 1-2 bucks a pound