A pest is any animal or plant detrimental to humans or human concerns. The term is particularly used for creatures that damage crops, livestock and forestry, or cause a nuisance to people, especially in their homes. Humans have modified the environment for their own purposes and are intolerant of other creatures occupying the same space when their activities impact adversely on human objectives. Thus, an elephant is unobjectionable in its natural habitat but a pest if it tramples crops.
