Terms relating to age

[Lovok]

I've noticed that the two yellow spots on Scylla's head get smaller and smaller w/ each shedding, and eventually they'll disappear entirely, which made me wonder (don't ask where it came from)...

Are there any terms for age ranges for snakes, and how do you tell where they are on the "Age Number Line"? On the far end you have "adult", on the other end is "hatchling", but what about the stuff in between? I've heard terms like "juvenile", "sub-adult", and the like, so I'm curious when Scylla can be expected to move from kid, to teenager, to all-grown-up, to cranky old grandma....

[guidofatherof5]

I first must apologize for not seeing your post and replying sooner.

I've never heard of a garter snake losing their head dots with age. I'd sure like to hear more about that. What species are we talking about here?
I believe the terms you mentioned might just be terms used by the keepers.
I use those terms to describe my snakes with a mix of age and size to determine what I call them.
Not sure there is a set time schedule by which to call them.

Once again sorry for the slow response to your question.