There are millions of species living in soils. Most of this biodiversity is made up of bacteria and fungi, tiny organisms that make up what is called the soil microbiome. The size and composition of the soil microbiome is mainly controlled by two groups of predators: protists and nematodes. Protists are tiny single-celled organisms, while nematodes are tiny worms and the most numerous animals on Earth. Protists and nematodes together weight more than all the other animals on Earth! Protists and nematodes keep the soil microbiome in balance, which helps plants to grow and keeps soils functioning properly. Without protist and nematode soil predators, the functions and services provided by soils would change so much that it could even affect the Earth’s climate. So, let us not forget the importance of these tiny soil organisms!