This seems like a largely ineffective method compared to marking with urine or feces, especially when dealing with matter so pungent, so experts believe this is unlikely. Its fun?! Theres no mistaking a dogs sheer delight as they roll about, often oblivious to our despair. Some scientists believe the behavior triggers a rush of dopamine, a neurotransmitter involved in reward and pleasure. While the behavior likely served an important function in dogs evolutionary past ...