How do rats dig holes?

Cross-sectional view of dog and mouse hole in African grassland. The cave has two exits, one is flat and the other is a raised dome. Biologists suspect that the woodchuck and the mouse piled one of the holes into an earthen bag in order to build a viewing platform with a wide view, but if this hypothesis holds, why didn't they pile both holes with earthen bags? Aren't there two observation platforms? In fact, the shapes of the two holes are different, which determines the direction of air flow in the holes. The wind blowing over the flat surface has low speed and high pressure; The wind blowing over the raised surface has high speed and low pressure. As a result, the wind on the ground blew into the caves of dogs and mice, bringing cool wind to dogs and mice.