Dogs have far more smell receptors than humans, and they also have an organ we don't that's specifically used for smell perception.

Beyond the shape of a dog's nose determining how well it can suss out scents, the internals are crucial.

First and foremost, there are 60 times more "olfactory receptor cells" in a dog's nose than in a human's nose. Think of it like cups for catching rain: If you have five cups set up to catch rain, you'll catch five cups worth; if you have 300 cups set up to catch rain, you'll catch 300 cups worth. That is the difference, roughly, between humans and dogs in terms of scent perception.

And that's not all! There's also the "vomeronasal organ," which is another means of deciphering information from scent molecules. "They're also getting information in the vomeronasal organ," Horowitz told me. "And to get information there you have to actually absorb some of the molecules."

This is why a dog might eat something it shouldn't — it's an attempt to learn more about that object. It also might just be hungry and ambitious.