When they are born they have only a few small feathers and need the heat from their mom to keep warm, but by the time they are a few weeks old they are starting to get feathers like the chick in the picture below!
When the babies are 3 weeks we take over caring for them and hand feeding starts. They are usually fully weaned and ready for their new homes at 8-10 weeks.
Each baby need lots of nutritious food to grow into a fully grown healthy chick. You can see our feeding program for each breeding pair and their babies on the page Our Budgies Diet.