I agree, switch him to small/small rats, one a week, in the 40-50 gram range.


Medium is much too large for him, and that's most likely the reason he's now refusing, assuming that all his husbandry is correct (correct temps, measured by a digital thermometer, small enough enclosure, tight enough hides and not overhandled).

As for his age, you really can't tell ages, as they all grow at different rates.