Boris really likes motion outside his tank. I do all I can, as frequently as I can, to entertain him. I hit upon this a few days ago. I dance this orange bandana in front of the aquarium. He comes to it, watches, swims around then stops and watches again. He's definitely reacting to the bandana. I can't tell if he's really excited or just interested - but it's good that he's interested. I'm looking around for other ways to enrich him. I got some good ideas from another thread, the best, I think, is to give him live food. I'm working myself up to that.