Definition - What does Pest mean?
A pest is a creature that is detrimental to human or human controlled interests including the cultivation of crops and the rearing and domestication of animals. The ways in which pests cause detriment to human interests are specific to each pest itself. Pests are widespread in nature and are often considered as a nuisance both in agriculture and domestic life.
Safeopedia explains Pest
Some of the most common pests include mice, which can bring diseases with them, as well as locusts, which come in hordes and destroy vegetation. There are also plant pests like weeds that compete with crops for nutrients from the soil. Plant pests are often controlled by using herbicides, while insect-based pests are usually controlled by using insecticides.