My pictus cat "Crackers" has decidely gone bananas. He used to just hang out in the caves and venture out sometimes. But I noticed yesterday that he spends all day swimming up one side of the tank and then halfway across the back of the tank. He only swims up and down one side, and only halfway across. He never goes the whole way. He looks healthy, eats well and seems to be doing fine other than this new behavior. Is this normal? Or has my Crackers lost his crackers