What role do animals play in nature?

Animals play an important role in the formation of the biosphere. If it is theoretically assumed that all animals have disappeared, then it is not known exactly what will happen to the plants and to the climate. The main functions of animals:
– participation in food chains, and various animals can act both in the role of food and in the role of its consumer, that is, animals regulate the number of each other and plants;
– participation in gas exchange – breathing;
– participation in the formation of the composition of the soil, for example, decomposition of dead animals.