Animals can be classified as either vertebrates, which have backbones, or invertebrates, which do not. Vertebrates include mammals, birds, reptiles, amphibians and fish. Animals can also be classified based on how they are born, whether from eggs or live birth, how they obtain food as carnivores, herbivores or omnivores, how they move around based on abilities like flying, swimming or slithering, and where they live on land or in water.