my blue tang and fox face do that and now my maroon and gold is joining the mix, I think they are more driven by curiosity and trying to search for food
You know there is super sweet people, loving cats, devoted dogs, lovable birds. Who's to say there isn't the same in the fish world. Look at how dauphin have been reported to save human lives. Something to make you say "Hymm!"
The interactions are actually much more opportunistic and practical than you may expect. Many herbivorous fishes are also incidentally coprophagous (i.e. they eat other fish feces) and so they will often trail other fish awaiting the next little tidbit. It is of great benefit for these fish, especially herbivores, since it helps distribute and enhance intestinal bacterial flora and optimize digestion of algal material. A win-win situation as far as the fish are concerned.
