Dogs align themselves with the Earth's north-south axis when going to the bathroom, and the smallest changes in the Earth's magnetic field can influence their position.
Seventy dogs from 37 breeds were observed defecating 1,893 times and urinating 5,582 over the course of two years, a study published in the journal Frontiers in Zoology reported.
The team found the canines tended to align their bodies with the north-south axis when defecating.
The researchers found the dogs did not usually exhibit the behavior when under "unstable conditions," FOX News reported.
The dogs only aligned themselves during times of "calm" magnetic fields, which is prevalent for about 20 percent of the day, Frontiers in Zoology reported.
"It is still enigmatic why the dogs do align at all, whether they do it 'consciously' ... or whether its reception is controlled on the vegetative level (they 'feel better/more comfortable or worse/less comfortable' in a certain direction)," researchers from the Department of Game Management and Wildlife Biology at the Czech University of Life Sciences in the Czech Republic and the zoology department at the University of Duisburg-Essen in Germany wrote, FOX News reported.
"Our analysis of the raw data ... indicates that dogs not only prefer N-S direction, but at the same time they also avoid E-W direction," they wrote.
The study marks the first-ever evidence that dogs are sensitive to magnetic forces and that they react to magnetic fields.
"Natural fluctuations of the Earth's magnetic field have previously been suggested to disturb orientation in birds, bees and whales, and even to affect vegetative functions and behavior in humans," the researchers said, the Daily Mail reported.
"In this study, we provide the first clear and simply measurable evidence for influence of geomagnetic field variations on mammal behavior. Furthermore, it is the first demonstration of the effect of the shift of declination, which has to our knowledge never been investigated before," they said.
