How does pastoral literature use animal imagery?

In 'Tess of the D'Urbervilles', Hardy uses animal allegories around Tess to position her as an innocent, natural being threatened by the wealthy characters who are more connected to metropolitan modernity, in the same way that 'field mice' are crushed under the modern 'threshers' in Chapter Eleven. She is also described as breathing like a 'wild animal' in the final chapter at Stonehenge to illustrate the fact that she has been unfairly hunted down, and treated as less than human.