Babies have more bones than adults because as they grow up, some of the bones fuse together to form one bone. This in turn is because babies have more cartilage than bones. New born babies have around 305 bones. A baby's skeleton is mostly made of cartilages. As a person grows up, most of this cartilage turns into a bone in a process called Ossification. By Adulthood, the skeleton has just 206 bones. Isnt it a real WONDER???