It sure was a weird feeling the first time my cleaner shrimp "cleaned" my hand when I put it into the tank! He will take flakes out of my hand and go back to the powerhead where he hangs out to eat. I used to think it was because he wasn't getting any business from my fish, but he really seems to like picking at skin. Good thing his claws are so small!
Yeah, those marron clowns are territorial-they bump and nip my hands whenever they get the chance. I still like 'em though.