Do I Have Worms?

[MMAX]

I was looking at my live rock today after a bit of maintenance and saw a few critters that looked like fan worms. I'm fairly positive that they are; a segmented white tube about 1/4 inch long with waving tenticles sticking out the top. Whenever they get frightened they go back inside their tubes. What kind of fan worms are these and how big do they get? Do I have to worry about my other tank occupants making a snack out of them?

[Myka]

Just little tube worms. They are a sign that your tank is starting to mature a bit. You should eventually find some red ones too. They don't really get any bigger. They won't cause any trouble, but Butterfly fish will eat them.

[tang daddy]

If it's the fan worms with a hard tube depending on colour they generally stay small althoughI got a few pieces of lr with the red/white fanworms they have a white tube inbedded in the lr they keep growing and are alot more noticable then when I first aquired them.
Usually reef safe fishes leave them alone however there are a few fishes that do like fan worms like a tang.