Mammals are vertebrates within the class Mammalia which have a neocortex (i.e., higher brain functions), hair, three middle ear bones, and mammary glands. Explore different types of mammals in the animal kingdom and their characteristics.

Birds are a collection of warm-blooded vertebrates within the class Aves, identified by feathers, toothless, beaked jaws, the laying of hard-shelled eggs, a four-chambered heart, and a well-built yet lightweight skeleton system. Explore different types of birds in the animal kingdom and their properties here.

Reptiles are four-limbed (aka tetrapod) animals within the class Reptilia. Discover different types of reptiles in the animal kingdom and their characteristics here.

Amphibians are cold-blooded, four-limbed vertebrates within the class Amphibia. Explore different types of amphibians, their habitats/ecosystems, diets, evolution, and characteristics here.

Fishes are the aquatic animals within the class Anatidae that do not have limbs with digits. Identify different types of fishes, their habitats, diets, predators, fun-facts, and characteristics here.

Insects are the largest group of six-limbed (aka hexapod) invertebrates within the class Insecta. Explore the world of insects here.

Crustaceans are a large, diverse group of arthropods (i.e., segmented body with jointed-limbs) within the class Crustacea. Explore the universe of crustaceans here.

Arachnids are another joint-legged (8-legs) invertebrate animals (arthropods) within the class Arachnida. Click here to explore the world of arachnids and their characteristics.

Echinoderms are marine animals classified under the class Echinodermata. All echinoderms in adult form contain radial symmetry (e.g., sea stars). Discover different types of echinoderms and their characteristics here.

Worms are animals with a long cylindrical tube-like body with no limbs. Check out different examples of worms and their unique properties here.

Mollusks are invertebrate animals within the class Mollusca in the animal kingdom. At present, about 85 thousand species of mollusks are recognized & properly classified. Learn more about them here.

Sponges are bottom-dwelling sea creatures within the class Porifera in the animal kingdom. They do not have tissues; Their body does not have symmetry like humans. Discover more about sponges here.