We all know that many animals seek refuge from the elements in the ground. The more extreme the climate or sensitive the creature, the more likely they are to live underground. Many of these animal homes are marvels of engineering with clever ways to deal with unwanted moisture and uniform distribution of fresh air. I am sure I could do a whole section on some of these interesting creatures, and I will when I have time ;^)
Eventually, all the animals will catch on… ;^)