The rats found throughout the novella are a symbol of physical, moral, and psychological decay. They first appear when Wilf goes back to check on Arlette’s body, which he pushed down the well. At first, he thinks that Arlette is moving and trying to talk, then he sees a “rat that had been chewing on the delicacy of her tongue” (27). It emerges from her mouth, tail first, forcing open her jaw and clawing on her chin. After, it drops onto her lap, then is joined by a “flood” of others that emerge from Arlette’s clothing. From there, the rats repeatedly appear throughout the novella, consuming Arlette’s body, attacking Achelois, biting and nearly killing Wilf, and then appearing as hallucinations to Wilf in the hotel room at the story’s end.

Because this is supernatural horror, it is unclear how often the rats are physically present and how often they are just a figment of Wilf’s imagination. In this way, the rats underscore the theme of The Psychological Consequences of Evil. They are a physical embodiment of decay and destruction, literally eating Arlette’s body and destroying Wilf’s livestock. At the same time, they overwhelm Wilf’s psyche. They are present, at least in Wilf’s eyes, in his home, in the clothing factory where he works, in the library, and in the hotel room where he dies. The further Wilf gets from the farm, the more likely it is that the rats are projections of his tormented mind. However, rats can infest urban spaces like factories—with their abundance of waste and dark corners—and libraries—full of paper and other materials for nesting—especially in the early 20th century.