The answer is actually pretty straight-forward... The human mouth is actually considered one of the dirtiest mouths among animals. In fact the human mouth contains so much bacteria, a human bite is considered more "dangerous" from an infection standpoint that a bite from a dog. During the day, we constantly swallow and eat/drink which washes away the bulk of the bacteria. We also brush our teeth and gargle our mouths which also helps. Unfortunately, during the night, none of the…