This passage describes the different types of mammals.

Lexile Level: 660L

Categories: Animals & Nature

Do you ever have trouble remembering what a mammal is? Most mammals have three things in common. Mammals have hair, feed milk to their babies, and are warm-blooded. People are mammals and so are tigers, hamsters, dogs, and dolphins. There are three kinds of mammals. They are monotremes, marsupials, and placental mammals. They are grouped according to how they have children. Monotremes are egg-laying mammals. Marsupials' babies are usually born in a pouch right on the mother's body, like kangaroos or koala bears. Placental mammals, such as humans, horses, dogs, and cats nourish their young inside with a special organ called a placenta. Most mammals must eat a lot to sustain their high body temperatures. Some mammals eat only plants. They are called herbivores. Others eat only meat. They are called carnivores. Mammals that eat a combination of both are called omnivores. Some mammals, such as aardvarks and anteaters, eat only insects. These animals are called insectivores.

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