The terrestrial mammals are fewer in number of species than lizards, but they are huge in individual numbers, and far more important in the life of the terrestrial biomes. Their ability to move from place to place and adapt has made them a most effective group. Many mammals live in cold places. These mammals have thick hair or blubber to keep them warm. Others may live in rainforests. On land the rodents (rats, mice) are hugely successful, more common in numbers than any other mammals. Large mammals on land have been hunted to extinction in some parts of the world, but the ones which remain are now better protected.