Bristle worm? ID please

[LeeR]

hello everyone, I just started my first reef tank a few weekds ago and i have noticed about 10 to 20 of these weird spinny worms that come out of small holes in my live rock, they never fully come out and if i even just tap the glass they squish back into there hole and wont come out for a few mins.. anayways i just want to know if these are good or bad i have looked around on google and nothing has come up that looks anythign like what i have so i will attach a picture. thank you.


sorry about the *crappy* picture if no one can IDit i will try to get a better picture tomorrow, when there is better light.