What is an example of foreshadowing in the novel, Leave the World Behind?

Deer appear multiple times in the novel and serve as a foreshadowing symbol of the apocalypse. In Chapters 1-2, deer are mentioned in the context of being unintelligent animals; they "strutted into the streets, walleyed" (6) only to be hit by cars, or they "strayed into attractive nuisances" (like swimming pools) "and if you were away for a couple of weeks, the stupid thing would drown, swell, explode, a horrifying mess" (8). But later, deer are depicted migrating en masse, and the narrator suggests that they are responding to the crisis occurring all over the world: "A miss migration. A disaster response. A disaster indicator. A disaster unfolding" (231). This indicates they are actually very intelligent and intuitive animals, despite humans' preconceived notions about them.