Pest (biology)

A pest is an animal which harms humans or human concerns. It is a loosely defined term; it overlaps with the terms vermin, weeds, parasites and pathogens. In its broadest sense, a pest is a competitor of humanity.
Top ten pests.
According to BBC News Science &amp; Environment, these are among the top ten pests of plants: Fungi are prominent in their list, and it is more usual to call them pathogens.