brumation's the reptile version of hibernation, with technical differences due to cold-blooded vs warm-blooded animal physiology.
in nature, snakes go dormant/inactive/brumate (the verb being brumate, the noun brumation) each winter. Temps decrease; daylight gets shorter (or they go underground where it's completely dark); they reduce feed or go off food completely. This enables them to survive inhospitable conditions--from occasional freezes in central florida to months of hard freeze in northern states where snakes are native. And it triggers hormonal responses necessary for reproduction--the production of sperm, ovulation in females.
In captivity, we do this by lowering their temps (even 60 is fine, imho). Reduce light--i adjust a timer til lights in the snake room are on ever shorter periods, til only half an hour or hour each day; some people throw a dark cover over cages & black them out completely. And we withhold food (they wouldn't digest properly at lower temps anyway, nor would they be inclined to eat when they're cool--nature has its ways of regulating things pretty well). OR some people keep babies warm throughout the winter (those that are feeding well) to get them additional growth. But the winter prior to breeding, they should be brumated.
Good luck! If you'll allow me, I'd like to suggest also that you spend some time with your milksnake and get the many details of management mastered, before you add additional animals with slightly different food & maintenance needs, etc. I think you'll feel better adding to a collection when you have that added confidence in their care.
And lastly, if you run across a small-enough lizard, that might tempt your milksnake to eat, too.
peace
terry