Bristle worm for sure. There not bad, expecially if they are in your fuge, I have plenty in my fuge, they are scavengers so definatly good for clean up porpuses. I persoanlly would leave them be. I had them in my tank as well, added a coral banded shrimp and he seems to have cleaned them up in the DT for me, but Ive left them alone in the fuge.