A small rat every 2 weeks won't make a ball python anywhere near that small at 8 years. That snake is either no more than 2 years, or he was not being fed a small rat every two weeks. At 8 years and that size, that's more like a small mouse every two months... one small rat every two weeks is not too bad a schedule. At 8 years, if the snake were healthy and fed well it would only need one medium every 2-3 weeks