Mammals, a class of vertebrates, are distinguished by several key features, including mammary glands that produce milk to nourish their young, hair or fur covering their bodies, and a neocortex region in their brains, which plays a role in complex behaviors and cognitive functions.

Mammals exhibit a wide range of adaptations to diverse habitats, from the soaring heights of birds to the depths of the ocean.

They are endothermic, meaning they can regulate their body temperature internally, which often allows for greater activity and exploration of various environments.

Mammals give birth to live young (with the exception of monotremes like the platypus and echidna, which lay eggs), and parental care is often extensive, contributing to the survival and development of their offspring.

With over 5,400 known species ranging from tiny shrews to massive whales, mammals inhabit nearly every corner of the globe, playing vital roles in ecosystems as predators, prey, and ecosystem engineers.