Given below are some really interesting facts about mammals. I am sure you will love and enjoy reading them. Almost all the mammals live on land. Bats are the only mammals that can fly. Dolphins and whales are the aquatic mammals. With a couple of exceptions, mammals give birth to live young. Platypus and Echidna are the two mammals that lay eggs. Elephants have huge feet and can weigh more than five tons. But their feet are big, soft and spongy that spread their weight out so well they barely even leave footprints. Eucalyptus is used to make cough drops; now because koala bears eat so much eucalyptus, they smell like cough drops. This smell helps them keep fleas away. Giraffes protect themselves by being big, so their goal is to grow as large as they can, as fast as they can.