I had a Northern Brown Snake give birth in captivity about a week ago and now I want to keep them over the winter to watch their progress. Only prolem is, I've never had experience with hibernation before. For years I've been observing Brown Snakes, Garter Snakes, and sometimes young Black Rat Snakes that I found in the yard during my "spring clean-up" but have always released them by the fall where I found them and let them hibernate on their own. In the last week I've literally become obsessed with my seven new additions and would hate to do something wrong. Currently they're in a 15gal terrarium with a pretty even dirt/gravel split about 2.5-3 in deep, many hiding spots, water supply, and heating pad. They're all doing great - eating has been no problem and they all seem very content.
I know that this species hibernates (have found groups of them in the early spring just emerging from their hibernation) but is this something that they have to do? I really have no problem with them hibernating, but I do want to make sure that I do it right. Any advice would be greatly appreciated! Thanks.

