What is a mammal? A look at three orders of this class of animal shows how certain characteristics allow them to be grouped together.
Ungulates - Learn what keeps these horses, hippos, and camels together in this seemingly disparate group.
Proboscidea - Watch how African and Indian elephants - put their elongated noses and trunks to good use.
Cetaceans - Learn how water mammals manages such incredible tasks as giving birth to live young under water.