A mammal is a vertebrate animal of the class Mammalia. Mammals are characterized by several unique features, including:
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Mammary Glands: Mammals have milk-producing mammary glands for feeding their young.
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Hair or Fur: Mammals have hair or fur on their bodies, which helps them survive in cold climates by insulating their bodies.
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Neocortex Region of the Brain: Mammals have a neocortex region of the brain, which is involved in higher-order brain functions such as sensory perception, cognition, and language.
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Three Middle Ear Bones: Mammals have three middle ear bones, which are involved in hearing and are unique to mammals.
Mammals are divided into three groups: monotremes, marsupials, and placentals. Monotremes are the platypus and echidnas, and the females lay soft-shelled eggs. Marsupials give birth to small, poorly developed young and most female marsupials, such as kangaroos, wallabies, and the Koala, have pouches. Placental mammals, like humans, whales, rodents, and bats, differ from monotremes and marsupials in that they generally give birth to well-developed young. All mammals produce milk to feed their young, have hair or fur, have a unique jaw structure, and are warm-blooded.
