Mammals

The National Wildlife Federation

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Mammals—a group that include humans—are warm-blooded animals with hair and vertebrates, or backbones. Unlike other classes of animals, female mammals produce milk to nourish their young. Almost all mammals give birth to live young (except for the platypus and echidna, which lay eggs).

Scientists have identified more than 5,400 mammal species on Earth, roughly one-fifth of which are known to be threatened or extinct. One of the most threatened order of mammals is the primate, which includes monkeys and apes. The United States has more than 400 mammal species. Of those mammals, nearly a quarter are listed on the U.S. endangered species list for reasons including habitat loss, climate change, pollution, and disease.

Bats

Nocturnal, flying mammals that eat fruits and insects

Bats	Indiana Bat
Jamaican Fruit-Eating Bat	Little Brown Bat

Rodents

Gnawing mammals with a single pair of incisors

American Beaver	Black-Tailed Prairie Dog
Dusky-Footed Woodrat	Flying Squirrels
Pocket Gophers	Red Squirrel
Red Tree Vole

Lagomorphs

Gnawing mammals with two pairs of incisors

American Pika	Snowshoe Hare
Swamp Rabbit

Moles and Armadillos

Burrowing mammals

Moles

Nine-Banded Armadillo

Carnivores

Meat-eating mammals, such as bears, felines, and canines

Black Bear	Canada Lynx
Florida Panther	Gray Wolf
Grizzly Bear	Hawaiian Monk Seal
Mountain Lion	North American River Otter
Polar Bear	Raccoon
Red Fox	Red Wolf
Wolverine