A category crisis emerges when an entity embodies and combines elements that do not and should not go together. As a result, this entity refuses easy categorization, and blurs the lines between one distinct category of another, creating a permeable boundary. According to Jeffery Jerome Cohen’s monster theory, the monster is a harbinger of category crisis because “they are disturbing hybrids whose externally incoherent bodies resist attempts to include them in any systematic structuring. And so the monster is dangerous, a form suspended between forms that threaten to smash distinctions.”
Carnivorous plants are harbingers of category crisis because they feature active trapping mechanisms that enable them to lure, catch, kill, and digest small prey animals (mainly insects), and absorb the resulting nutrients. The trap’s movement reacts to the muscle contraction of animals, but plants do not have muscles and nerves. How could plants react like animals?
A plant that feasts on animals is wonderfully unsettling because it shatters all expectations and consequently, this entity refuses categorization as an animal or a plant. Insects suffer the ultimate indignity for an animal: to be killed by a plant. Carl Linnaeus, the 18th century Swedish naturalist who devised a system for ordering life, rebelled at the idea. For plants to eat insects, he declared, would go “against the order of nature willed by God."