Need ID - Fanworm or Aiptasia?

[BetteMidler]

Just noticed this on a frag I got just over a week ago. Only shows itself at night? If I increase the light or shine a light, it retracts quickly. Not seeing a tube yet if it is a fanworm.



Do I need to intervene & take action?

 

[EeyoreIsMySpiritAnimal]

Feather duster. Harmless

 

[BetteMidler]

Feather duster. Harmless

Thank you! I have feather dusters all over my entire rockwork. Do you think it came with the frag or has it spread there from my rockwork that quickly?

 

[EeyoreIsMySpiritAnimal]

Thank you! I have feather dusters all over my entire rockwork. Do you think it came with the frag or has it spread there from my rockwork that quickly?

No idea