That was a quote from Sabine Begall, a research who has determined that dogs have a compass-like sense of direction when it comes to well, you know, pooping. Apparently they sense the Earth’s magnetic fields. Here’s another quote from one of the researchers:

Dogs prefer to face north or south but only when the Earth’s magnetic field is stable, which it often is not. A lot of the time, the magnetic field is kind of wobbly and unstable. And when that happens, the dogs will drop their payload, well, any which way.

 

Read more at the NPR website for All Things Considered.