Rachel knew what was in the bowl, and recoiled slightly. "Professor, there are rat tails in the bowl right? Well, the only reason I see is that the concept of rat tails has always scared people. That means that if it is used in a potion with other specific ingredients, then it will create the same effect; hair raising," she said. She wasn't 100% sure of her answer, but she reckoned that it was the best she could do.