Nice corn snake! Actually any non feeding colubrid should be evaluated for injury, illness, shed cycle in preparation to brumate. It's a natural thing for them to do and their internal clocks tell them when it's time. Even the young non feeders that refuse live foods especially can benefit from a short cooling cycle. While it's true that brumation is done mostly for breeding purposes it's also a remedy for non feeders regardless of age, after all of the previous mentioned possibilities are ruled out. True brumation calls for a gradual reduction in temperatures and varies on acceptable set temps for different species. Definitely for breeding, brumation is key to maximize the maturation of the sex cells and increasing the potential litter/ clutch size. Steven Bol(famous garter snake breeder) has had his extensive brumation/ hibernation research study published on his website and chronicles his methods including baby and juvenile garter snakes. His website is Steven Bol Gartersnakes. This is a brand new study results that he reports on.