I remember watching a Mama house wren using a tasty morsel bug to teach her babies to fly. Somehow they got from the bird house to the fence. Then Mama would land next to them with a bug in her beak, baby would open up, and Mama would fly away a couple of feet. Baby would get a clue and fly to Mama, who'd fly away. After a couple of these jumps, baby would get the bug as a reward. Then Mama would fly off to get another bug, and give a lesson to the other nestling. Seemed after an hour or so of practice mini-flights, all three birds headed to a shrub to rest.