New Stone Age
By around 7000 BC there started to be more people in Greece. This may be related to the Black Sea catastrophe which happened about this time. Maybe because of refugees from this disaster, it became harder and harder to get all the food you needed just by gathering and hunting. So people began to farm. Farming was more work (and not as much fun as picking wild berries and nuts), and the food you got wasn't as good for you and was pretty boring, but you could feed more people on less land. People also began to herd sheep.
Once you are farming, you also need to build fences to keep out the deer and rabbits, and to keep in the sheep, and people also began to build houses. Probably there weren't enough caves for all the new people, though people were still living in Franchthi Cave at this time too, and still sailing around in little boats.