A study of 70 dogs of 37 breeds in 2013 found that pooches circle before they poop, seemingly to align their spines with Earth’s north-south axis. The effect was seen when Earth’s magnetic field was stable, but disappeared when solar activity caused it to fluctuate. Just like migratory birds and salmon, it seems that dogs can sense Earth’s magnetic field, but instead of using it for navigation, they use it for defecation! Dogs poop on the Earth's north-south axis and may be able to sense Earth's magnetic field. - Image credit: GettyThis article is an answer to the question (asked by Ann Moore, via email) 'Why do dogs circle round and round before pooping?'