Kangaroos are grey-brown, red-brown or golden-brown marsupials, meaning they are pouched mammals. Their young are born extremely undeveloped, about the size of a kidney bean,
…and make their way from the mother's birth canal, up a track through her fur which she prepares by licking, to her pouch. There, the joey latches onto a teat which swells in its mouth so it cannot be accidentally dislodged during the mother's movements. The mother kangaroo is able to feed two different aged joeys simultaneously with different milk which meets each joey's nutritional requirements. Kangaroos' ears are pointed and able to move in many different directions as they listen for potential dangers. They have large hindquarters and long feet with which they can hop for long distances. They do not tire, as the hopping motion actually refills their lungs as they move - therefore, there is minimum expenditure of energy. There are a variety of different sizes of kangaroos, and they are classified according to their sizes. (MORE) 
