Female mammals are a group of animals that belong to the class Mammalia. They are characterized by their ability to produce milk to feed their young, a feature that distinguishes them from other animal classes. Female mammals typically have two X chromosomes and possess reproductive organs that allow for gestation and childbirth. Most female mammals give birth to live young, although some, like monotremes such as the platypus, lay eggs. Female mammals can be found in various species, including humans, dogs, and whales, and they play essential roles in their ecosystems, often caring for their offspring until they are independent.