I agree with Tom for keeping these guys feeding. It also helps to offer live food. I've had similar problems with Russian Rats at times, going off food even in August. It's because their active season is so short and they are getting ready to hibernate. Some ratsnakes also migrate at this time of year, and some might even change prey items with the changing season. I offer live fuzzy or pinky mice to keep them feeding.
Where I live just above the 45th parallel the nights are getting cool, in the forties. That's when the snakes are starting to cool down too, and they don't eat near as much. They become more opportunistic and eat smaller meals. I think Kunasiri Island is even further north than this in Japan.
One problem I've had is keeping these snakes (don't keep climacs anymore, but still have Russians) brumating until spring too. Then if you start them too early, they go through their normal activity period (around six months) earlier, and then want to rest. That's what they're adapted too. But they also respond to the climate in your area. It depends too on how close to wild caught they are, of course, as to how strong their instincts are. I try to keep my snakes like this going at least until sometime in October before I attempt to brumate them.
Hope this helps...
TC
>>They are notorious for hunger strikes. One change I made with my colony was to switch from adult mice to fuzzy rats (just about no hair). They took hairless items more frequently. That's a great idea to record their eating reponse to identify each individual's pattern.
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