Age and size seem to matter more to them calming down than handling does for the most of it. Babies are 6" long with a 60' attitude, it's laughable honestly, and at that size often won't sit still in your hands much before trying to shoot off and run away. It seems like somewhere around 12-18 months old, it's like they wake up one day and are suddenly a totally calm and laid back, different animal. I have four adult breeders and none have ever been handled, so long as there isn't a scent of rodent in the room, I can handle any of them and do not expect to get bitten.