GabyThere are a few reasons dogs love to stick their heads out of moving car windows. Dr. Helen Pilcher, a biologist and science writer from the UK, calls it a “sensory buffet.” Dogs see fewer colors and are often nearsighted, but their field of vision can stretch up to 250 degrees (compared to our 180°). They also register more visual frames per second than humans do. So while the scenery may appear blurry to us, it can look quite sharp to a canine passenger.
Scents matter even more. A dog’s nose holds about 300 million olfactory receptors—humans have around 6 million—and the brain area that decodes chemical signals is roughly 40 times larger in dogs than in humans, Science Focus reported.
When humans exhale, the air leaves the body the same way it entered. When dogs exhale, however, air escapes through slits on the sides of their noses, creating currents that pull in new smells. That lets dogs sniff continuously, so airflow from an open car window is basically rocket fuel for their noses.
But there’s a simpler reason, too: dogs enjoy it. Pilcher says they peek out for the same reason we love a convertible—because it’s fun.
