Mysteries of My Neighborhood #2

Here's a very strange yard. All the ground, including the parking strip is covered in black plastic then tanbark. There are a couple of street trees, an oleander bush or two and a couple of fruit trees. That's it. The windows always have the shades down. Alice saw a young man step out of the house once. We met once there those Guatemalan greyhounds walkng by. Those are the only signs of animal life there.
Why the sterile zone? Allergies by the human occupant(s)? No one seems to know.
Alice says it reminds her of the little house on one of her classmates' family farm. A little house that was really just to disguise an air shaft and elevator down to a US Air Force forward controller bunker for a big field of nuclear missle silos in the area. The people below came up a few times a year to mow the prairie grass around their house and once a year to a BBQ given to them by Alice's classmate's parents.
Maybe the people in the little white house near my house are just retired USAF missileers wanting to feel at home?