The more plant species live in grasslands and forests, the more insect species find a habitat there. However, the presence of more plant species does not only increase the number of insect species, but also the number of insect individuals. Simultaneously, animal diversity is not only determined by plant diversity, but also by the physical structure of the plant communities. These are the results of an international collaboration led by the German Centre for Integrative Biodiversity Research (iDiv), published in the journal Nature Communications. These results have consequences for the insect-friendly management of grasslands and forests.