Yes they r bristle worms and their not bad. If you find that at a certin point you have too many of em just get your self a coral banded shrimp. he will have a feast of a time eating them. just to make sure do what i do touch them. if your hand doesnt burn their bristle worms and if it does burn well i feel sorry for hand for a little while. Besides if they are fire worms you got to get rid of them or else your coral will b in trouble.