worms that come out at night

[jorg21775]

I have all these little tube worms that come out at night from the live rock. One of them was about half inch wide and 5 inches long and came to a point(only saw it once). The rest of them are small like a 1 inch long and 1/8 in wide. They are not bristle worms. Just wondering if anybody can inform me on what they are and if they are a thret to my tank. Thought the six line would take care of them but i dont think he is helping?

[jformani]

not sure what they are but i have them in my tank as well. they expand then retract sometimes getting 6-7" long. i've seen them trap crud when they expand and actually real it back in and crud is gone, so i keep them!!!

[TorisFishes]

without any pictures it could be anything.