In 'Twice', the quote "It is still unripe, Better wait awhile; Wait while the skylarks pipe, Till the corn grows brown", the use of Zoomorphism ("Skylarks") are often associated with the changing of seasons, particularly spring, when they are most active - The reference to skylarks, then, can be seen as a symbol of the passage of time, particularly the idea that waiting for emotional or spiritual growth requires patience - The birds’ song in the poem reflects the hope that, in time, the speaker’s heart will mature, much as the earth naturally transforms through the seasons