Having a hard time discerning hydroid or feather duster

[krookedsession]

As the title says I am struggling with determining these are hydroids or feather dusters in my display tank. They retract when the tongs come nearby. I also have what i believe are feather dusters in my sump on some rock i have in there. Any help would be appreciated

 

[Crabs McJones]

I see both, first picture is feather dusters, second is hydroids, third are feather duster tubes and pineapple sponges

 

[krookedsession]

Interesting, both the first and second picture when I view those forms look nearly identical and retract and behave similarly. I wasnt prepared for it to possibly be both haha. Ill keep monitoring

 

[Leadfooted]

Halloween Hermit!!!!

Its unfortunate many don’t know. It’ll destroy your hydroids leaving a perfectly clean rock.