Why do birds have hair when they hatch?

A baby chicken might look like a ball of fuzz with legs and a beak, but that’s not hair covering its itty-bitty body. Rather, it’s a layer of fine feathers called “down,” which traps heat to keep the chicks toasty. (Down is such a good insulator that it’s used as stuffing in pillows, jackets, and sleeping bags.) as the baby birds grow, they sprout tougher, more feathery-looking feathers on the top of the down. Their bare skin is all covered, but the tail grows out last since it is too large to effectively grow while chicks are in the nest. At this stage, precocial birds have a good number of mature feathers but may have a scruffy appearance until they lose the last of their down.

 

Picture Credit : Google