KW's Law of Possession

Once your saliva has touched something it is yours. This is why it is a good idea to spit once you get outside. If you are inside people get upset if you spit, in this situation you can claim items by licking them.

Your tongue can also play a role in self defense. Most attackers don't want to be licked, if someone comes in for an embrace it is a good idea to lick them and let them know you mean business.