Why do dogs sniff each others hind quarters?

I bet you have been asking your self this very question a few times. Carla’s late grandfather once told the reason and it has stuck with me ever since.
You see, a long, long time ago there was a dog party being held and it was one grand party. If you were any kind of quality dog you had to be there. The party was so popular, in fact all the world’s dogs were there.
The dogs hung their tails in the cloak room as soon as their entered the party because this was a party with style. They received numbered tickets to properly identify their tails.
The party was lavish and there was a lot of dancing and sausage eating. One big fat female dog was barking with a smooth voice.
Suddenly panic broke out because a fire had started in the basement of the mansion. All the dogs were frantically running around and rushing for the exit. There was no time for searching for the right tail; each dog grabbed first tail available and hurried on out.
And this is why to this very day dogs still are looking for their own tail. Every time they meet a new dog they first check whether this tail could be their old misplaced one.