How do you know it does not affect the snake? Just because it eats and breeds does not mean it has an optimal quality of life.
Since we can not understand the language of 'snake' we have to use measures that we can extrapolate information from- like eating and breeding.
~~McKinsey~~
"Men have forgotten this truth," said the fox. "But you must not forget it. You become responsible, forever, for what you have tamed."
~The Little Prince; Antoine de Saint Exupery