Why is farting funny?

Possibly because it is a chance to make that person who farted embarrassed and want to crawl in a hole and just sit there forever. Or it could be because there are many different sounds you can make with farts like you can squeak or you can blast or even sound like a Trumpet or an owl. Farting has its risks too because you don't know when you are going to set off a stink bomb. So be careful about who you are with when you fart because if you are around the wrong person they will be disgusted and you will be so embarrassed it's not even funny.