The amount of changes a baby chicken goes through in the first 8 weeks of life is amazing to watch. They start as a tiny ball of fluff, no bigger than an egg (literally). Within 8 weeks, they’re fully-feathered, smaller versions of their adult selves.
Even though they’re only halfway to maturity, it seems that they have made much more than half the changes and growth needed to be an adult.
At hatch, the baby chick has no feathers, only fluff. It quickly figures out how to walk, eat and drink.