Mary Allen
We call beneficial animals that are useful to humans. Most people think of spiders, insects, bacteria, or nematodes. They eat other insects that we call pests. These are, for example, lice that attack flowers and vegetables.
People distinguish between beneficial and harmful animals, thinking of their own advantage. For nature itself, there is no such difference: everything that lives contributes to the cycle of life and is needed. But people mostly see it from their own point of view.
Beneficial insects are not necessarily related to each other. They do not form their own animal species, genus, family, or order. A house cat is also useful to humans if it catches mice or rats. And a cat is certainly not biologically related to a spider.
Instead of fighting the pests with chemicals, more and more people are using beneficial insects: lacewings or ladybugs eat lice, nematodes bore into the maggots of cockchafers, and so on. In this way, the pests are destroyed without side effects, or at least there are fewer of them. In this way, nature itself is used to combat pests.