Whenever it happened, the explorers changed the local population's outlook. Along with their intelligence to make ceramic cooking pots, they also brought rats in their grain. Within two generations, people faced extreme physical violence from each other because of their switch from hunters to farmers. To grow cereal and herd cattle, they needed land and, with it, protection from anyone wanting to take over. From then on, ownership played a major role in events. They armed themselves with weapons, not for their prey, but for their neighbors.
The human population increased because of the life-style so they could no longer hunt. No going back. The rats took advantage of the food supply.
Now days in our overpopulated land, we worry about people taking our parking space. Those who haven't overcome their hunting instinct catch fish or shoot birds, targets, goals. Some compete in sports, fashion, jobs or even cooking. So far, the Pied Piper hasn't led the rats away.