The art and science of agriculture embrace most intentional human efforts to control biological activity so as to produce plants and animals of the sort wanted, when wanted. Rubber plantations, cattle ranches, vegetable gardens, dairy farms, tree farms, and a host of similar enterprises all represent human efforts to compel nature to serve man. Those who undertake agriculture have had, from time immemorial, a variety of names, not all of them complimentary. The people involved in attempted biological control have been called farmers, planters, ranchers, and peasants. Farmers carry on a complicated business in which they use a variety of tools, implements, and machines. They also employ land, chemicals, water, plants, and animals. Their business, however, focuses on living things. No matter how crude their attempts, or how uncertain their successes, those who try to grow living things rank as agriculturalists.