Vermin (colloquially varmint(s) or varmit(s)) are pests or nuisance animals that spread diseases and destroy crops, livestock, and property. Since the term is defined in relation to human activities, which species are included vary by region and enterprise.

A pest is any organism harmful 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 when it tramples crops.