Mammals include humans and all other animals that are warm-blooded vertebrates (vertebrates have backbones) with hair. They feed their young with milk and have a more well-developed brain than other types of animals.

Giraffes grow about 4 feet (1.2 meters) in their first year of life. A newborn giraffe is about 6 feet (1.9 meters) tall at birth and weighs about 150 pounds (68 kilograms). Many young giraffes, called calves, die from lion attacks during their first year of life. Once a giraffe reaches adulthood its height is often enough to protect it from lions. Adult giraffes, however, must still be ...

African elephants can live up to 70 years! Learn more amazing facts about the African elephant with National Geographic Kids.

Most marsupials have pouches where the tiny newborns develop. A koala mother usually gives birth to one joey at a time. A newborn koala is only the size of a jelly bean. Called a joey, the baby is blind, naked, and earless. As soon as it's born, this tiny creature makes its way from the birth canal to its mother's pouch.

Get Weird But True! facts about mammals. From animals to geography, take a look at these amazing—and slightly strange—facts about our world. Skip to content

Weird But True: Marine Animals. Weird But True: Marine Animals. Penguin facts and photos

Fastest mammal on land, the cheetah can reach speeds of 60 or perhaps even 70 miles (97 or 113 kilometers) an hour over short distances. It usually chases its prey at only about half that speed, however. After a chase, a cheetah needs half an hour to catch its breath before it can eat.

Chimpanzees are omnivores, meaning they eat both plants and animals. Young chimpanzees learn from observing their mothers and other adults which foods are safe to eat and where ripe food is located. For the first few months of its life, a baby chimp clings to its mother's belly as she travels with it everywhere. After that, young chimpanzees will spend the next seven to ten …

Gentoo penguins like to hunt for fish, krill, and squid! Learn more amazing facts about the gentoo penguin in this video from National Geographic Kids.

Very social and playful mammals, bottlenose dolphins form friendships that last decades hunting, mating and protecting each other. They like to surf in the waves and wakes of boats and swim through self-made bubble rings. They can swim up to 22 miles an hour. These sea mammals feed on fish, squid, and shrimp. A group of dolphins will cooperate ...