It’s no secret that dogs like to lick a lot. Why is the behavior so common and why do they lick people, cats, and other household animals across species?
Let’s get the obvious out of the way first. Licking is instinctive, probably on par with a sucking response in all mammals. Recent studies have shown that behavior is also related to canine neurophysiology.
When dogs (and probably other mammals) lick, their brains release endorphins. This term is being used more and more every day, but I bet few out there know what this class of chemical is. Most just know that it means something good and we should get more when we can, like when people run long distances.