I am gonna go out on a limb here and guess the sidewinder is the little worm that Bob G gave you. Since the animal is so small it could be that the food items are too big or more likely that you need to throw a heat lamp on him for a few days to get his digestive tract churnin. I have raised a few from birth in the past and they usually do real well once they get started. Just warm it up into the mid 80's or so and it should be fine. If that doesn't work it could be a few other things but hopefully it will.