I think im going to have to try the ping pong ball idea with my Flowerhorn as he seems to get very bored, do you just leave them in the tank with the fish, or just put them in for a "play time" every so often?
Its not something that i trained him to do, but if i am in the room and do not pay him at least some attention every so often, he will pick up small rocks and spit them at the glass to get my attention then stops as soon as i talk to him for a second. He also has a bad habbit of dismembering the fake plants in his tank (doesent eat them, just pulls em apart) and he will freeze and look at me if i yell for him to stop lol.