Although Charlotte Elizabeth Tonna's 1839 social reform novel Helen Fleetwood has long been understood as a commentary on the dehumanizing effects of factory work, her use of animals to represent factory workers has not been considered in analyses of her depictions of dehumanization. Considering both the growing interest in the animal/human divide during the early nineteenth century and Tonna's own direct contributions to discussions about animals, in this essay I examine the role that animals play in negotiating definitions of humanity and nature in the novel. I argue that idealized, "Edenic" animals and corrupted, "industrial" animals are integral to Tonna's juxtaposition of the pre-industrialized countryside and the industrial city; I also explore how "animality" transcends the content of the novel and becomes an element of the novel's methodology and conventions. Using the animality of Helen Fleetwood as a case study, I conclude that Victorian social reform writers not only idealized nature to serve their arguments but were also constrained and somewhat undermined by a kind of "nature" that lay beyond their narrative control.