The Exploratorium's "Explainers" program trains local high school students to answer visitor questions. The old space hired around 120 Explainers, but the program has more than doubled, making the Exploratorium the largest employer of high school students in the city, says George Cogan, the Exploratorium's chairman of the board. Explainers don't just talk the talk, however. They get their hands dirty with science. This collection of carnivorous plants is being grown and maintained by some of the Explainers in the biology-based Living Systems section.