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. From elephants to snails, animals come in many shapes and sizes, and can be found all over the world.
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.
There are more species of animals than in all the other kingdoms combined. From worms, to blue whales, to bald eagles, animals have evolved to fit a wide variety of niches.