Once they land on grass, a robin locates earthworms by cocking its head to the side to see. With eyes on the sides of its head, a robin has monocular vision and can see independently with each eye.
According to Wild Birds Unlimited, a robin can consume up to 14 earthworms in a single day. Worms not consumed on the spot are often brought back to the nest to feed the young. Robins are especially drawn to open lawns following periods of rain and after grass is freshly mowed, conditions that make it easier to search for earthworms and other insects.