I had 3 of them on my rock and I took the piece out of the water and ran extremely hot water over hem and they usually fall right off don't pick them they will regrow! Any little piece left behind wil start new growth! Ahhh!! The other thing I did was took my needle syringe and injected there mouths with again hot water and same thing fell right off! My peppermint shrimp dont touch these, but aptishia they have it destroyed in 3 days usually! Good luck. Hope u get them guys gone.