"Mammals are our closest relatives in the animal kingdom; most are beautiful, and many are highly intelligent and have intricate social systems. They are found in all kinds of habitats; they may have fur, scales, or spines; they move by hopping, swimming, running, or flying. What all mammals share, apart from certain anatomical similarities, is the unique ability to nourish their young with milk from mammary glands.Many species of mammal ..."