Dogs and cats by their very nature have characteristics that make wandering common. Both are highly curious by nature. Their close relatives include wolves and tigers, both of which hunt and check out new areas of interest continually. Exploring and chasing objects of desire is an instinctive action for household pets; even if they receive proper attention and care at home, because by their nature they will have an inkling to find out what lies beyond their territories, and sometimes that longing can’t be denied.
Dogs in particular have several forces that could potentially propel them out the door. For starters, just the smell of another dog in heat could spark their procreation urge. Neutering and spaying reduce this likelihood by about 90 percent, but that leaves a small percentage of fixed animals that are ruled by pheromones. Another way their noses get them into trouble is by smelling food. If a tasty treat from afar tempts them enough, they’ll seek out its source. Also, if they’re not being stimulated enough at home — puppies and certain breeds have tons of energy and need proper outlets for it — they can run away out of sheer boredom.