PLEASE get him OFF of the pine as soon as humanly possible. It can cause irreversible lung and kidney damage from the oils in the shavings.

Pine or cedar should never be used as the oils produced by the shavings are caustic and cause alot of internal problems. Use aspen, bed-a-beast, cypress mulch, newspaper, paper towels, small children, ANYTHING(except for carpet, it's just gross all around). You are causing your snake harm keeping him on that bedding. Please change it immediately.