Animalia
Like many other lifeforms, animals are multi-cellular. These cells come together, forming tissues, organs and organ systems, that help sustain the life of the animal. The cells of animals have a nucleus. From horses to snails, animals come in many shapes and sizes, and can be found all over the world. There are more species of animals than in all the other kingdoms combined. By far most species of animals are insects, with groups such as molluscs, crustaceans, and arthropods also being especially diverse
Animals cannot make their own food. They must rely on other living things, such as plants, fungi, and other animals to sustain them. Without other food sources, animals could not survive. Most reproduce sexually, by means of differentiated eggs and sperm. Some animals can reproduce asexually eg worms.
Animals are classified mainly due to the presence or absence of a notochord - or in simple terms, a backbone. These groups are vertebrates and invertebrates.