death from old age?

So I was thinking recently, what happens when a ball python (or any snake for that matter...) comes to the end of its life naturally?
Does a snakes immune system fail near the end of its life, leaving it open to disease and infection? Does it stop eating and die of starvation? Does it keep eating normally and one day just expire? It seems to me that it might be a very long process, and that most would put their animals down if experiencing health problems if they are 25+ years, but I base this on nothing, and want more experienced keepers input!
My snakes are very young still, but I just thought of how sad it will be after living with the snake for (hopefully) 30+ years...
I tried to search with no luck, and this may be more appropriate for a different part of the forum, but since my interest is currently vested in bp's, I thought I'd post here.
Speculations, experience, and research is all welcomed! Thank you for your time!

They are animals just like us. They can die from the same types of diseases as any other animal (i.e. organ failure, cancer, illness, etc.). There is no way to predict the mode in which any animal, big or small, fuzzy or scaly. will die.

Like us, their cells are probably just "programmed" to stop dividing at a certain age...and when that happens...death.