Humans and all other creatures living on planet earth are animal. This is an obvious statement with few exceptions. Animals are multicellular, living organisms in the Kingdom Animalia. With few exceptions, all animals eat organic matter, breathe oxygen, can move, reproduce, and die. All other animals, plants, and fungi are protozoa, eukaryotes, in the Kingdom Protista.
Insects are the most diverse group of animals making up the animal kingdom. There are about six hundred thousand species of insects worldwide. Some of the insect groups include: butterflies, dragonflies, aphids, caterpillars, fleas, moths, and Stinkhoffs. The majority of insects are aquatic, but a few insects are land animals and some are aquatic and land animals. Most insects are warm-blooded, while there are a few insects which are cold-blooded.
Domestic animals, also known as fauna, belong to the class that includes wild animals. Virtually all mammals, as well as many reptiles and amphibians, are domestic animals. Many domestic animals are used for food, but not all animals are used for entertainment. Birds entertain humans with their songs; fishes entertain us with their colorful swimming pools and aquatic plants give nourishment to domestic animals; and cats entertain us with their felines. Nearly all domestic animals have been domesticated or have become extinct.
All forms of vegetation are organisms, and all forms of animals are alive. A cabbage patch is not a cabbage, nor is a potato. All living things, both animal and plant, contain cells that are made up of living matter. Cells in plants grow, divide, and die. Organisms and plants differ in that the cells of plants grow, divide, and die in a nonstop manner while the cells of organisms grow, divide, and die in a nonstop manner.
Every living animal has certain characteristics that distinguish it from other animals, plants, and insects. All living things, whether animal or vegetable, possess organs and tissues that are designed for assisting the organism to obtain food, maintain an appropriate environment and excrete waste. The eyes of an animal or insect allow the creature to see; the reproductive system of an animal allows reproduction to occur; the lungs of an animal and its ability to respire enable the animal to survive. Individual organs and tissues exist to enable the animal to live and provide a proper environment, and each of these necessary functions is described by an animal body.
An animal kingdom is described by thousands of different kinds of organisms with unique features that make them distinct from one another. These examples include every kind of bird, mammal, reptile, amphibian, algae, fungus, cyst, bacteria, and every kind of invertebrate. Some examples include the eye of the bat, lungfish, butterfly, shark, snail, vampire bat, tiger, chinchilla, manatee, salamander, and tortoise.
