We used to have a couple in my old neighborhood.... One had his/her den next to a culvert under the street and thanks to the den, it washed out enough for a pickup to fall through the asphalt pavement...
The other one was building it's den in the hill leading to my neighbor's in ground swimming pool and the neighbor requested it gone, but not in front of his wife or daughters... Mission Accomplished from my deck... /ubbthreads/images/graemlins/grinning-smiley-003.gif
Usually they build their dens in the sides of ravines near a food source and water...whether it's tubular plants or the edge of a crop field..