I have one male and 1 female. They are both right at a year old. Both born same month last year. The girl eats 1 medium rat every 14 days and 1 small rat every 14 days on alternating schedule now. She is almost 800g. Why do I change it up for her? Is what she prefers and works for her. I was doing small rats every week and she was always hungry. She doesn't need a medium every week and when she does eat a medium she will not go 14 days between feedings. It works for her. Took some doing to figure this all out. My male is 575g and eats 1 small rat every week. The girl is slightly longer and slightly larger around. Neither of them are to fat or under weight. Keep in mind I am not an expert but took time while treating them as independent personalities to make them happy. Their growth has been slow and steady. Never refused food and eat pre-killed just fine.