What are the respiratory organs in soil animals?

Breathing in the soil is possible because there is air. But the composition there is a little different. First of all, the concentration of carbon dioxide and other gases is much higher than on the surface. This is the reason for the appearance of structural features of the respiratory system of underground animals. Worms are able to breathe over the entire surface of the body. Various rodents and moles have lungs. In moles, red blood cells work a little differently. The connection of erythrocytes with hemoglobin is weaker than that of land animals. This is typical for those animals that are in a state of constant hypoxia.