We are used to looking at life above ground, but there is a huge variety of life in the soil, as well.
The surface of the soil is a rich source of dead leaves, seeds, nuts and berries. The soil is also a place to hide from hunters. The soil is also warmer than the open air in winter and cooler and moister in summer.
But it is difficult to move around in the soil, so all of the animals have to have ways of tunnelling.
