Cat spazzing is a fairly regular occurence at our house. Cecil will run around the house, jump on the bed, chase his tail, attack Selphie, try to hamstring Randy, etc. I guess he just has extra energy to burn off after sleeping all day. Selphie will run around with him too, though she is a bit calmer than he is at most times. Our old cat Calvin would on a fairly regular basis run around my parents' house at top speed and attack his teddy bear. The cats my mom has now, Tigger and Pooh Bear also like to run around the house occasionally. Mostly Tigger though -- Pooh Bear is fat and lazy, so not as much.