Who got blamed for chirping?

Mrs. Avery doesn't know where that weird chirping sound in the classroom is coming from. It's Nick Allen, of course, the resident troublemaker, goofing off as always. But he gets away with it, because he's perfected the skill of mimicking a blackbird without being discovered. He learned this from watching a nature program on TV. Apparently, a certain species of blackbird is able to throw off hawks and other predators by emitting a high-pitched chirping sound whose source they can't identify. As Mrs. Avery resembles a hawk with her curved nose, she is the predator and Nick is the prey. And like the blackbird, he's able to distract his would-be predator by giving off a strange sound. He's so successful that he never gets caught. Poor old Janet Fisk gets the blame instead.