Can I see this pudgy 6 y/o, 1500g BP? Small rats monthly seems like a pretty strict maintenance diet. I think some snakes have different body types just like some people. As long as he’s healthy and not morbidly obese I wouldn’t feed him any less than once a month. If you want to slim him down I guess you could force a fast on him but I wouldn’t do that until winter. I have 3 carpets that are all roughly the same age and on similar feeding schedules (every 3-4 weeks) but one is quite a bit thicker than the other two even though I’ve been feeding him medium or large rats while the others eat large and jumbo rats. The only difference between them is the one snake eats all year while the other two fast for 4-5 months during the winter/breeding season.