There are a number of theories. One is that they are giving a 360-degree look at their surroundings before getting in that vulnerable position. Another is that they are spreading their scent to mark their territory – kind of like with pee marking. Then there’s the theory that they are making themselves a nice, clean place to go to the bathroom. And then there’s the magnetic field theory. This one claims that dogs use the force of the Earth’s magnetic fields to choose their pooping place, preferring the north-south axis of the Earth. According to researchers at a university in Prague, dogs prefer to “excrete with the body being aligned along the north-south axis.” Well, there you have it … sort of.