The human body can be a fascinating (and disgusting) thing at times and the mouth doesn't get the attention it deserves for how weird and wonderful it can be. For example, we all know that saliva is produced to help digest food and most know it has antiseptic qualities, but did you know that the average human produces enough saliva in their lifetime to fill two olympic swimming pools? This is based on statistics which state that we produce nearly 300 litres a year (or around a litre a day)! Now that's a lot to swallow....