Ripening for Destruction (?)

We have a tomato plant that has little tiny green tomatoes on it. Peter looked at them and said asked when we take them off. I told him we have to wait until they are red and yummy. He wanted to know why we don't take them off now. I said they have to stay with their momma plant until they get big enough for us to eat. "Just like you," I said, "You stay with me until you are grown up then someone eats you, right?" He said, "No, nobody eats me!" "Then what happens?" I said. "Maybe somebody eats you?" says he. "-No, probably that doesn't happen either." We will figure it out eventually, I hope.