In a cramped, dimly lit room, three women stare at a bank of blinking video monitors. Each of the six screens shows, from a slightly different angle, a black-and-white ball of fluff—Tai Shan, the giant panda cub born last summer at Smithsonian's National Zoo. Every two minutes, at the ring of a bell, the volunteer researchers write down what the cub is doing. Ding! Sleeping. Ding! A yawn. Ding! The right front paw twitches. For the first two months of Tai Shan's life, Zoo staff and volunteers monitored him 24 hours a day. He is one of the most closely studied pandas in history.