High in dense bamboo forests in the misty, rainy mountains of southwestern china  lives one of the world’s rarest mammals: the giant panda, also called the panda. Only about 1,500 of these black-and-white bears survive in the wild.  Pandas eat fast, they eat a lot, and they spend about 12 hours a day doing it. The reason: They digest only about a fifth of what they eat. Pandas’ molars are very broad and flat. The shape of the teeth helps the animals crush the bamboo shoots, leaves, and stems that they eat. They can chomp on bamboo up to one-and-a-half inches thick.