Dan Falk in Undark:
Several chapters into “Aesop’s Animals: The Science Behind the Fables,” zoologist and science writer Jo Wimpenny explains that, as a very young girl, she sometimes wanted to be a dog. (In a footnote she credits growing up in Wales for encouraging her “to think outside the box.”) This childhood fantasy, as the reader can readily imagine, involved crawling along the ground on all fours. But that only gets one part-way toward doghood, as the grown-up Wimpenny would come to realize.
For starters, we humans rely primarily on our senses of sight and hearing, but for dogs, it’s smell that reigns supreme; as she explains, a dog’s sense of smell is somewhere between 10,000 and 100,000 times better than our own. Dogs “can also wiggle their nostrils independently, helping them to pinpoint the direction of a smell,” and there’s some evidence that the left and right nostrils serve slightly different purposes, with the right tuned to “novel and potentially threatening smells,” and the left responding to “familiar, non-aversive smells (such as food) and scent from other species (such as human sweat for tracking purposes).” Who knew?
More here.