Researchers have found that dogs use Earth's magnetic fields to align their bowel and bladder movements - and they prefer to relieve themselves along a north-south axis. In fact, canines will actively avoid going to the bathroom in an east-west direction, the study found.
After monitoring 70 dogs from 37 different breeds over a two year period, scientists from the Czech University of Life Sciences in the Czech Republic and the University of Duisburg-Essen in Germany found that dogs were more likely to poo along a north-south axis, determined by the Earth's geomagnetic field (magnetic north is slightly different to true north).
The findings, which were published in Frontiers in Zoology at the start of last year, were the result of watching a total of 5,582 urinations and 1,893 defecations (yep, just imagine how fun that would have been). The team then compared the positioning of the dogs during the acts to variations in the Earth's magnetic field.
They found that in calm magnetic field conditions, the dogs consistently preferred to be aligned north-south when they pooed. But perhaps the most striking result was that, regardless of magnetic field conditions, dogs blatantly avoided relieving themselves along the east-west alignment.
The reason for this preference still isn't clear. The authors wrote in the paper:
"It is still enigmatic why the dogs do align at all, whether they do it 'consciously' (i.e., whether the magnetic field is sensorial[ly] perceived) … or whether its reception is controlled on the vegetative level (they 'feel better/more comfortable or worse/less comfortable' in a certain direction)."
However, it's further proof that many animals are able to sense the Earth's magnetic field and adjust their behaviour accordingly. We humans also have a protein in our retina which may help some people detect the planet's magnetic field, but for most of us the ability is out of reach.
But at least we now know why there's so much pivoting involved every time our dog needs to go to the bathroom.
Find out more about how bird's use quantum mechanics to navigate along Earth's magnetic field in the UNSW Engineering video below.