Baby ferrets should be kept in cases with very small spaces between bars so feet don't get stuck. You should train them to use a litter box. Baby ferrets are weaned at 6 weeks so if they are younger they need food soaked in water to make digestion easier.
The most important thing you can do is to provide them with a very low hanging ferret sleep sack to keep them warm. Make sure they can very easily get in and out!
