Meaning of life is pest control
A pest is any living thing, whether animal, plant, or fungus, which humans consider troublesome to themselves, their possessions, or the environment.
To fit the dictionary definition of a pest, it must have three significant characteristics. For a pest to survive, it needs to have food and shelter, plus a place to breed. For an animal to become a pest, these characteristics have to clash with humans.
In its broadest sense, a pest is a competitor to humanity. A pest is any organism harmful to humans or human concerns.
It is a loose concept, as an organism can be a pest in one setting but beneficial, domesticated, or acceptable in another.
All organisms serve a useful purpose in the ecosystem, and are therefore, by default, beneficial. As the term is applied here, however, it means any living thing that benefits the environment around us (humans), including insects, spiders, mites, nematodes, birds, reptiles, mammals, plants, bacteria, fungi, and viruses.
The benefits they provide include pest management, pollination, and maintenance of soil health.
The opposite of beneficial organisms are pests. Any organism can be considered a pest, by humans, if it negatively affects those humans (see Is It Really a Pest? for more). These living things can be detrimental to human or other organisms’ needs.
Microorganisms, whether bacteria, microscopic fungi, protists, or viruses that cause trouble, on the other hand, are generally thought of as causes of disease (pathogens) rather than as pests.
I’m going to add, a pest is any organism (human, animal, insect, weather), disruptive, threatening or harmful to your own personal environment, or causing a nuisance in any way.
Humans have modified the environment for their own purposes and are intolerant of any other creatures occupying the same space when their activities impact adversely on their objectives.
Thus, an elephant is obviously admired in its natural habitat – but is a pest when it tramples crops.
Some animals are disliked because they bite or sting; snakes, wasps, ants, bed bugs, fleas and ticks belong in this category. Others enter the home; these include houseflies, which land on and contaminate food, beetles, which tunnel into the woodwork, and other animals that scuttle about on the floor at night, like cockroaches, which are often associated with unsanitary conditions.
Agricultural and horticultural crops are attacked by a wide variety of pests, the most important being insects, mites, nematodes and gastropod molluscs.
The damage they do results both from the direct injury they cause to the plants and from the indirect consequences of the fungal, bacterial or viral infections they transmit.
Plants have their own defenses against these attacks but these may be overwhelmed, especially in habitats where the plants are already stressed, or where the pests have been accidentally introduced and may have no natural enemies.
The pests affecting trees are predominantly insects, and many of these have also been introduced inadvertently and lack natural enemies, and some have transmitted novel fungal diseases with devastating results.
Humans have traditionally performed pest control in agriculture and forestry by the use of pesticides; however, other methods exist such as mechanical control, and recently developed biological controls.