Turns out your mom was wrong… having a dirty mouth isn’t always a bad thing. Our mouths are naturally filled with lots of bacteria—even though, yes, we know you brush—which is necessary to start the digestion process in your body. These microscopic germs keep fungus in check and even supply us with our own type of venom, as the human bite carries more bacteria than any other species. But did you know that vegetarians have cleaner mouths than carnivores? It’s the rotting bits of meat between the teeth that feed mouth bacteria in the first place. Not the best selling point for kissing carnivores, but fascinating nonetheless.