Predators, parasitoids, or pathogens provide an important ecosystem service in agriculture by limiting the population growth of plant pests. However, the type of land use, cropping systems, and frequent use of fertilizers or pesticides have strong impacts on animal and plant communities, as well as on the microcosm inside and outside croplands. For example, the species richness and abundance of natural areas is highly affected by land-use factors with the risk of disrupting natural pest control. We explore the needs of these organisms (food resources, alternative prey or hosts, nesting or overwintering sites) to make recommendations for agricultural practices to conserve and enhance them. In addition, the biodiversity of natural enemies themselves offers almost unlimited opportunities for innovative methods of biological control. It is just a matter of knowing and how to conserve and use them.