Cuckoo Song

What do you do? In April, I open my bill In May, I sing night and day In June, I change my tune In July, far off I fly In August, away I must What do you do? In April, I open my bill In May, I sing night and day In June, I change my tune In July, far off I fly In August, away I must What do you do? In April, I open my bill In May, I sing night and day In June, I change my tune In July, far off I fly In August, away I must