Here's a breakdown:
* Birth to 3-4 months: Giant panda cubs are entirely dependent on their mother's milk.
* 3-4 to 6-8 months: Cubs begin to wean, starting to nibble on bamboo while still nursing.
* 6-8 months onwards: Cubs transition fully to a bamboo diet.
It's important to note that this is a general timeframe, and individual cubs can vary slightly in their transition.