They couldn't interact because they were isolated from the other communities by the mountains and other natural obstacles. They were more likely to communicate with non-Greeks.
Ancient Greek farmers did not have enough flat land for farming normal crops grown during the time period, so they built wide earth steps into the hills to provide more flatland for farming. Also, they grew different crops, like: olives, grapes, and they began to raise goats and sheep instead of cattle.
The ancient Greeks ate what they could grow on the hilly, rocky terrain. These foods were olives, grapes, a little wheat and a little barley. They grew well on the rocky landscape. Hope this helped. ;)
