I had a related experience about 40 years ago. On our front lawn I saw a mother  
robin leading a brood of four or five baby robins showing them how to get worms  
from the ground. The baby robins were imitating, but along with the baby robins  
was a young ovenbird, appearing to be part of the brood, also digging for worms.  
I didn't see it actually eat a worm, but I watched them all for at least five  
minutes.

Bob