I typically kept two breeder females, so every time I had litters at the right stage, Luna would get one (two if she was particularly frisky) every two or three days for about a week or so (number dependent on litter size), then there would be a lag until the next litter. She's always been a little on the pudgy side, with the exception of one particularly long winter fast (the extra fat reserves became a necessity that year). At the little hopper stage, rat pups are basically bags of butter, so for animals with low metabolic rates and high assimilation efficiency (like pythons), a little goes a long way.