National Zoo Chief Veterinarian Suzan Murray (right) checks the panda cub's ears while Assistant Curator Lisa Stevens (center) holds the cub and Keeper Nicole Meese looks on. The cub squirmed and fussed throughout the exam, said zoo staff. Mei Xiang became anxious when she heard the squealing, and tried to squeeze through an 8-inch-square window in the den door to rescue her cub. She was eventually called away by one of the keepers, who offered her pears, apples and sweet potatoes in an attempt to calm her down.