I have been noticing these really fine strings along the sand bed, never thought anything about them until I decided to try to move them, there seems to be a small mound where all the strings lead to as I dug it up it was like a worm made out of jelly sand stuck to it like glue. i didn't realize it was alive until it started moving to buried itself again. I have 2 or three of these things now. Just curious if anybody knows what they are and are they reef safe? in the pick you can see the strings.