Odd-toed ungulates are a group of mammals that have either one or three toes. The three families in this order are the large and tank-like rhinoceroses, pig-like tapirs and the agile horses. The 17 species in this order can be found in Africa, Asia and even the Americas and include domesticated horses and donkeys. With their browsing and grazing lifestyle, they have a specially enlarged section of the large intestine in which bacteria live and help them digest their food.