Featherdusters annoying Zoas?

[Maverick00]

Ive been struggling the last few months with a couple small zoa colonies. Ive relocated them to a darker lit/ lower flow area at the bottom of the tank which seemed to help for abit but im once again watching them start to fade away. taking a close look i noticed more and more featherdusters on or near the colonies. Could it be the featherdusters are irritating the zoas to the point where they can not fully open and start dieing off? Its seems like there are more and more on the rock every month.