*whistles nonchalantly* Juuuuuuuust a sausage, doing sausage-like things. . . lol! Maybe he's self-conscious about his waistline, and doesn't want you to see him doing aerobics. I'm SURE he's measuring his girth - using the space between the tank wall and the intake to judge if he's lost any weight. That MUST be it!
When my fishy was in QT, I literally SNUCK into the room on hands-and-knees so that he wouldn't see me. He always came over to 'play' when he saw me, but I really needed to know how he was doing when he was all alone! Silly fishes. . .
heeeeeeeeey. . . are you SURE Sparky isn't a she? Just curious.