Some cats act old and crotchety when they are 7 or 8, while others still act like kittens when they are 12 or 13. Most cats, though, start to enter their senior years when they are 8 to 10 years old. Pretty Cats, Beautiful Cats, Animals Beautiful, Pretty Kitty, Animals And Pets, Cute Animals, Gatos Cool, Photo Chat, Tier Fotos