Mammals

Mammals are vertebrate animals constituting the class Mammalia and characterized by the presence of mammary glands which in females produce milk for feeding their young, a neocortex, fur or hair, and three middle ear bones. Although North America has some 400 species of mammals, most are by no means easy to find. True, Racoons catch our attention when they prowl around our homes, and bison are much too big to stay hidden in the grass. but the majority of mammals survive by being elusive. many, for example, avoid the light of day (a behavior pattern that also keeps them cool.) opossums and mink are primarily nocturnal; deer and rabbits are active mainly about dawn and dusk. regardless of the hours they keep, mammals, in general, are difficult to spot, for they blend into the background with ease. their fur-a feature unique to mammals (another unique trait is that they nurse their young)-is usually some shade of brown; some, such as the varying hare, even change color with the seasons to achieve year around camouflage. stripes or other patterns often break up the image (fawns are a prime example). many mammals and other animals too are pale on the underside, which offsets any shadow that might make them stand out from their surroundings. and few mammals are noisy enough to attract your attention with sound.
Category:Animals