Robin treats fledgling to a tasty worm. For the first four days of a nestling’s life, the parent birds regurgitate partly digested food into each baby’s mouth. By five days of age, the nestlings get earthworms that parents break into small mouthfuls. The babies eat more each day. Soon parents give them whole worms and large insects. Each young robin may eat 14 feet of earthworms in a two-week nest life—and worms are not even their main food! Did you know they start learning the sounds their parents make.