Belly rub addiction is most common in pets during their adolescent to later adult years. Not that this is a bad thing. Belly rubs are just as addicting for humans too.
Sometimes, dogs learn how to ask for belly rubs from their humans. This little pomeranian completely understands which signals to send to his human so that he could get some awesome bellyrubs.
But the most hilarious part is his reaction to the belly rubs! Brilliant!