live rock bugs?

[aceband2003]

This might sound weird,i recently purchased live rock with mushrooms on it,and i noticed 3 grey looking bubbles,which looks like bugs on the side of the rock. It does not move,just looks strange to me,any ideas or comments?

 

[Longnose Hawkfish]

A picture would help if you could get one

 

[Jerseyfresh]

Possibly bubble algae?

 

[ReeferEric]

If it moves, its a bug. Not likely bad but you should always dip corals that you receive.