English Across the Curriculum
A mammal is an animal that feeds its babies with milk when it is young. There are over 4,500 types of mammals. Many of the most popular animals we know are mammals, for example, dogs, cats, horses, cows, but exotic animals like kangaroos, giraffes, elephants and anteaters belong to this group, too. Humans are also mammals.
Mammals live in all regions and climates. They live on the ground, in trees and even underground. Polar bears, reindeer and seals are mammals that live in the Arctic regions. Others, for example camels or kangaroos, prefer the world's dry areas. Seals and whales are mammals that swim in the oceans; bats are the only mammals that can fly.
Colony of seals
Image: M. Boylan [Public domain]
Mammals have five features that make them different from other animals:
People have hunted mammals for ages.They ate their food and made clothes out of their skins. Thousands of years ago wild mammals were domesticated and gave human beings milk, wool and other products. Some mammals, like elephants and camels, are still used to transport goods. In poorer countries farmers use cows or oxen, to plough fields.
Animals ploughing fields in India
Image: ©Yann Forget - Wikimedia Commons
Mammals are often kept as pets. Among them are cats, dogs, rabbits or guinea pigs.
Mammals are useful to people in many other ways. Some help plants grow and eat harmful insects. Others eat weeds and prevent them from spreading too far. The waste of mammals is used as fertilizers that improve the quality of soil.