Snake’s skin has 2 layers, skin and epidermal. Epidermal renews periodically, it is the shed. The frequences depends on age, species, breeding’s conditions. In a healthy snake, the shed is in one piece, but big snakes could sheds in several times.
They have a lot of vertebras. Head’s bones are not linked, in order for them to eat easily a big feed in one time. They have a lot of teeths but they don’t cut their food. The cesspool is a sort of chamber for their urine. Lungsare bigger in the sun to take the heat, but the left one is mostly unexistant. They breath with the heat. They can’t ear but they see vibrations and their nervous system goes with reflexes. The moves of their body are generated by the brain. The Jacobson organ is really developed for their taste.
Snakes could see easily, but when they are in shed, don’t touch them because they can’t see so they are agressiver. They detect the heat to attack or to sleep.
We prefer to give them alive food like in their environment because we want that their natural instinct of hunt was preserved, but also because we want that they see the food with her heat. If you want to give them frozen food, you could because it’s easyer and safer. Indeed you have to survey the rats or mices and it takes times.