A recent story from Mexico may provide some clues. In 2006, a mysterious illness began to affect girls at a boarding school in Chalco, Mexico, near Mexico City. The school, which is run by Roman Catholic nuns, is one of 10 in Asia and Latin America operated by a charity called World Villages for Children in Asia.
There are also several marine mammals like Orca's (killer whales), harbor seals and sea lions that live in the Seattle area in the cold waters of Puget Sound and the Pacific Ocean and feed on the salmon and other fish. Douglas squirrels rely on the the evergreen trees that are native to the area.
The single largest group of mammals is the Rodentia. Most non-flying mammals are rodents: there are about 1,500 living rodent species (out of about 4,000 living mammals overall). Most people are familiar with mice, rats, hamsters, and guinea pigs, which are commonly kept as pets.he Rodentia also includes beavers, muskrats, porcupines, woodchucks, chipmunks, squirrels, prairie dogs, marmots, chinchillas, voles, lemmings, and many others. (Incidentally, the Rodentia does not include rabbits; rabbits differ from rodents in having an extra pair of incisors and in other skeletal features.