It depends on the person and the snake. Some snakes are more comfortable in the dark, and some are more comfortable in the light. some of my sankes, like Snap and Ember, prefer eating at night, when the tank is darker, and my northwesterns will eat better during the day when there's light. Really, you just need to find what works for your snake, they're all different... They are(like) people, too... No two snakes are the same.