Inhabiting the cool mountainous forested areas of Japan and some of its surrounding smaller islands, they can be found at elevations of between 500 & 3000m above sea level. Rob says this species requires similar temperatures to other mountainous species such as Euprepiophis mandarinus, avoiding temperatures over 28.5C as this will result in the snake going off its food. In the wild Euprepiophis conspicillatus feeds mainly on voles, lizards & amphibians. In captivity some keepers have reported that mice would often be refused. Contrary to this and the reported short seasonal activity periods from April to June and again during the autumnal months, Rob hasn't had this problem and his adults eagerly take defrosted rodents all year round.

To condition his adults for breeding he only ever brumates them for 6 to 8 weeks due to the mild temperatures experienced in his country throughout the winter, any longer than this they would experience too warm a temperature and begin to lose weight. Like many Ratsnake species they will breed after their post brumation slough. The clutch size for the Japanese Forest Ratsnakes is quite small with an average of only 3-5 eggs being laid, but can be as many eight. Rob's female this year (2008) laid 3 eggs, two of these measured 9 & 8cm long by 2cm wide, these are still in incubation as I write. In 2007 a clutch of 5 eggs were laid between the hours of 3 & 4am these in comparison to this year were a lot smaller measuring only 5cm. In 2006 the eggs again averaged 8cm but only two in the clutch. He says in previous years the clutch size always numbered three.

The babies, who unlike their parents are bright red with black markings, hatch after an incubation period of 50-55 days. Rob's experience with the hatchlings like other breeders is that they refuse all food offered to them after their neonate slough. He tried brumating the hatchlings one year, which is one trick employed for difficult feeders but sadly lost them all. Instead now he gives them a cooling at room temperature, leaving them well alone except for general maintenance until February. On being warmed up, they usually begin to feed and Rob recommends starting them on Mastomys mice pinkies as he has found they prefer these as a first meal. After a few meals of Multimammate Mice they usually begin to accept regular pinkies. Once feeding they are an easy species to keep although they will occasionally refuse to feed for a while, but he says this is no different to any other Ratsnake. Young animals are not brumated until they have enough fat reserves as along with the hatchlings mentioned earlier he also lost some yearlings, so is a little wary about brumating any young animal now.