red dwarf hermit

I have a few red dwarf hermit crabs and I noticed every night one climbs on top of my Zoanthus sp and eats something.
I think he is just eating algae, because Zoanthus doing ok. I took a few pics to show.
Any thoughts?



They are just about virtually mindless eating machines. All hermits are. By nature for some reason they like to play king of the hill and go to the top of the tank or the highest point in the rock structure. Perhaps it isn’t the top, but where they can get the best view for food.(or smell food the most.) I would say if the zoas seem to be fine I wouldn’t worry about it, just keep an eye on it.
Some reefers eventually remove every single hermit crab from their system or never add them. Some have tons. I have a couple tanks with none, but most have 2 in them. Mostly the tricolor/blue leg type.