Every dog owner knows how seriously their pet takes the decision of where to do its business. First it will pace in circles, nose to the ground, searching intently for the perfect spot. Once selected, there are another few turns and a shimmy until, finally, it is ready to commit. If you've ever wondered what's going through a dog's mind as it does this, the answer could be something like the spinning of a compass needle. Dogs prefer to defecate with their spine aligned in a north-south position, and they use Earth's magnetic field to help them position themselves.
展开▼
