Thomas Hardy was a nineteenth-century lad with a soft spot for animals. In his letters scholars have found evidence that Hardy cared for and was concerned with the wellbeing of nonhuman critters. So it's interesting to see how animals play a role in his novels.
Early in Jude the Obscure the novel's protagonist, Jude, shirks his responsibility to a farmer who has hired him to scare away birds in his field so they won't eat the seed he has laid down. Jude feels bad about keeping these birds at bay, and let's them have it—enjoying the sight of the birds fattening up. Jude identifies with these birds—he too is seen as a scavenger, a parasite, a good-for-nothing… we could go on.
Later in the novel, when Jude is an adult, he marries the daughter of a pig farmer and one day is forced to kill one of the family's pigs. It doesn't go well. Blood spills everywhere and Jude is super upset—Jude, like Hardy, has a soft spot for animals. The novel's human-animal interactions are compelling because they are clearly deeply meaningful in the novel, but not just as metaphors.
We get the sense that these interactions really mean something: that these animals have agency and effects on the fictional worlds around them.