Quote Originally Posted by snakelady View Post
Also, the black parts on my Ball Pythons can look blue in the sun because they have some iridescence to them.
Irridphores are the cause for the appearance that you see. The amount of irridphores in the skin cells, is directly linked to the ammount of irridescense that you see. Some snakes shine like a rainbow, and other have just a slight gleen to them. However, they are the cause for the blue tint you see on your snakes head.

As for your other questions, I think Connie did an excellent job answering them, so I'll leave it at that.