Rachel Carson begins her book Silent Spring with an allegory, explaining how a small American town with beautiful nature, one day is destroyed and all the birds stop singing.
There was a strange stillness. The birds, for example—where had they gone? Many people spoke of them, puzzled and disturbed. The feeding stations in the backyards were deserted. The few birds seen anywhere were moribund; they trembled violently and could not fly. It was a spring without voices. On the mornings that had once throbbed with the dawn chorus of robins, catbirds, doves, jays, wrens, and scores of other bird voices there was now no sound; only silence lay over the fields and woods and marsh.
Obviously she tries to convey the message how pesticides harm nature and she uses an allegory to make non-scientist readers understand what she means. But is there another reason for such use of allegory, and if yes, then what is it?