If your dog spins in circles or acts like a spaz before squatting to poop, don't worry: She just might be trying to align herself with the Earth's magnetic field.

We've known for a long time that animals use the planet's magnetic field, or MF, to orient themselves. Birds and sea turtles use it to travel unfathomable distances with stunning accuracy. Cattle, for whatever reason, prefer to align themselves along the north-south axis while grazing. Light-sensitive proteins recently discovered in the human eye suggest we may have once been able to even see it.

And dogs might use it to poop. According to a new study by Czech and German researchers published in the journal Frontiers in Zoology, a two-year analysis of more than 70 dogs from 37 breeds showed that our furry friends "preferred to excrete with the body being aligned along the north-south axis under calm MF conditions."

Earth's MF is calm only 20 percent of the time during normal daylight hours. When the planet's MF is thrown out of whack during something like a solar flare, the once-fastidious animals were suddenly less picky about their crapping preferences.

The same rules seemed to apply to both male and female dogs:

We found no differences in alignment of females and males during defecation and of females during urination, which might be related to a similar posture the animals are adopting during defecation (in all dogs) and urination (in females). Urinating males have a slightly different preference to orient their body axis than urinating females (cf. Figure 3); this could be caused by leg lifting during urination in males. Indications of different directional tendencies depending on which leg (left or right) is lifted are currently under study. [Frontiers in Biology, PDF]

Why dogs found the planet's north-south axis more comforting is unclear, though no less remarkable. The findings might even warrant a quick double check the next time you take Chloe out for her morning number two.

Source: Boing Boing