Everybody poops. And for most of us, bowel evacuation is a pretty straightforward process. In the animal world, however, things can get a little more complicated. Take, for instance, the world's first domesticated mammal. When nature calls our dogs, she often seems to have some pretty elaborate instructions.

Specific canine rituals and routines will vary based on breed, age, location, weather, and a bunch of other variables, but in general the act of expelling solid bodily waste is not the simple, opportunity-based activity it is for humans. There is sniffing and wandering. There is spinning and digging. Sometimes there's additional wandering, and maybe even a false squat or two before the final package is delivered. As many dog owners will attest, this hunt for an elusive fecal bullseye can be exhausting.

So what exactly is going on during these intricate performances? Like pretty much everything else that relates to physiology and animal behavior, there isn't one simple answer. In general though, you can thank your dog's keen sense of smell and the complex social dynamics he inherited from wolves for this finicky behavior.

Also, magnets. Well, magnetic fields to be precise.

Poopertunity Knocks ——————-

It's 13 degrees outside, your ears and fingers are starting to go numb, and once again Rambo can't seem to find the right spot. That snowless area by the shrub looked promising 10 minutes ago, but now he seems to be following some invisible breadcrumb trail to your neighbor's lawn. You know he needs to go. Why can't he simply do his business so you both can return to the House of Cards marathon you started in your temperature-controlled apartment?

Here's what people tend to forget about dogs (and a number of other animals): Elimination fulfills both a physiological purpose and a social one. Whether the deed is done in an open field, the middle of the street, a neighbor's doorstep, or a bed of ivy, dogs are not just expelling bodily waste; they are depositing piles of really interesting information on the ground.

The precise location can depend on the type of message they want to send or answer, among other things. In the wild, wolf packs will typically create an "olfactory bowl," leaving their feces and other scent markings (urine, paw scratches) along the perimeter of their territories. The message? Stay out! Studies have shown wolves also prefer to poop along trails and roads, particularly at junctions, places where other packs and individuals can easily "read" the intended message.

For domesticated dogs, the inclination to both search out and leave these calling cards remains strong. "These messages can tell your dog how many other dogs are in the immediate area, the sexual status of those dogs—whether a female is in heat, for example—whether a particular dog is a friend or an enemy, what he or she had for lunch, and when they were last in the area," says Carlo Siracusa, director of the Small Animal Behavior Service at the veterinary hospital of the University of Pennsylvania.

All that information is encoded in a combination of pheromones, ammonia, and gland secretions and can be deciphered with the 300 million olfactory receptors dogs have in their noses. In fact, for some dogs, it's precisely these types of olfactory stimulants that trigger the urge to eliminate and mark.

Pooformance Anxiety ——————-

While these social signaling behaviors can and do inform the places and amount of time it takes your dog to do his or her business, it's also important to remember that, like humans, dogs are individuals with their own personality quirks and preferences.

Put another way, physical distractions and certain predispositions can have the same effect on dogs as they do on us. That big, loud waste management truck with the terrifying trashcan-grabbing arm? What living thing could poop with that thing lurching down the road?

According to Melissa Bain of the Clinical Animal Behavior Service at UC Davis' School of Veterinary Medicine, dogs develop preferences for elimination at a young age—like what type of surfaces they like going on.

"They seem to prefer softer substrates, if they have the opportunity to use them," she said in an email. "They are also attracted back to the area on which they eliminated before, so if it smells like urine or feces, they are attracted to go back there (providing it's reasonably clean)."

Puppies learn to "hold it" and also gain the ability to make positive associations with certain surfaces at approximately 8 1/2 weeks. Dog owners can obviously have a big impact on those preferences, which tend to stick over your dog's lifetime. In other words, if your dog grew up on or near a beach, sand may hold a special allure that grass or tanbark could never match.

Pole Poosition ————–

You may have noticed another odd thing about your dog's pooping habits: Spinning or abrupt turning before final release. There's the normal crouch, but it's frequently followed by a number of directional recalibrations. What's that all about?

According to a 2013 paper published in Frontiers in Zoology, it may be that dogs attempt to align themselves with Earth's magnetic field before pooping. Specifically, they seem prefer to defecate along the North-South axis if the magnetic field is stable.

After spending two years gathering data—observing 5,582 urinations and 1,893 defecations—and ruling out things like the influence of wind, time of day, and sun angle, the researchers found that the only factor that determined how and where the dogs popped a squat was Earth’s magnetic field.

The paper is interesting, and could very well indicate dogs possess some sort of magnetosensitivity, like birds, whales, and bees. But as Siracusa points out, for all the things the researchers did control for, they did not seem very interested in things like substrates, their inclination, and all the other important behavioral characteristics we've just gone over. Bottom line? There are factors far more important than magnetic fields that regulate the direction of your dog's bottom.

Like intelligence. Sometimes all the dilly-dallying has nothing to do with socio-behavioral factors like searching for triggers or gathering information. Sometimes dogs just like being outside.

"A lot of the time, particularly for urban dogs, they are brought outside only for urinating or pooping," Siracus says. Dogs quickly learn that once they complete these things, the party is over and you immediately bring them back inside. That may run counter to Fido's goals, so he simply puts nature’s call on hold.