Feather dusters in a moon coral?

[Aaarrrggg]

I got my first LPS last week, a moon coral;

I've read how the polyps extend at night-time to feed, so I was surprised when 4 tiny feathery 'hands' started extending under full lighting. They come out of little yellow rimmed holes (in the green part of the coral)...reach about and twist around before retreating again.

What are they? Are they part of the coral or some kind of hitch-hiker...and if so, are they bad?

Any info would be much appreciated
Thanks!

edit: photo just to show what sort of moon I'm talking about...you can't see the 'thingies' I'm refering to...they're pretty tiny. I might be able to draw a pic if needed for ID.

 

[unbreakable]

i have the same kind of coral as yours and i have a feather duster and a mini bristle starfish in there. so far it hasnt bothered anything and it's been there for a month. wouldn't know how to take it out though

 

[Opcn]

Do they come out and go back in in a fast manner, if that is the case it could be barnicles.