According to your description those pups are about 2 weeks, 1 to 2 more week and you will be able to wean them from their mom.
Keep in mind that whatever goes in the rat’s belly will end up in your snake’s belly.
You want to feed healthy food to your rats.
Quality Rat food can be found in feed stores near you, a 50 lbs bag should cost you around $20 and will last a long way if you only have few rats.