Mammals

#Google SEarch

It's natural for people to consider mammals the pinnacle of evolution--after all, humans are mammals, and so were our ancestors. (In fact,mammals are among the least diverse animal groups—there are only about 5,000 species overall!) Mammals are characterized by their hair or fur (which all species possess during some stage of their life cycles), the milk with which they suckle their young, and their warm-blooded metabolisms, which, as with birds, allows them to inhabit a wide range of habitats, ranging from deserts to oceans to arctic tundra. .