I just had the total opposite happen. I've had a problem with my zoas getting a light brown algea on them causing them to stay closed, 2 days ago i had a snail (only snail i have) molesting them, i was close to pulling him because it looked like he was eating them, but because of my line of work i avoid putting my hands in the tank. He seemed to clean them without hurting them, now they are open and algea free. But definitely gonna keep my eye on him now and make sure he wasn't snacking.
Sent from my SM-G900P using Tapatalk