The American robin’s diet generally consists of around 40 percent small invertebrates (mainly insects), such as earthworms, beetle grubs, caterpillars and grasshoppers, and 60 percent wild and cultivated fruits and berries. Their ability to switch to berries allows them to winter much farther north than most other North American thrushes. They will flock to fermented Pyracantha berries, and after eating sufficient quantities will exhibit intoxicated behavior, such as falling over while walking. Robins forage primarily on the ground for soft-bodied invertebrates, and find worms by sight (and sometimes by hearing).
Both parents cooperate in raising the young, which they feed a diet consisting almost entirely of insects. Some young stay around the nest to help raise another brood. Fledglings are grayish in color, with speckled breasts. The blue color becomes much more prominent and the speckles on their breasts disappear as they mature. Bluebirds may begin breeding the summer after they are hatched.