We ran a duplicate of Stanford University's "Marshmallow Experiment" with our own Flood kids (Google it for the details).
If they could delay gratification by sitting in a room alone with one marshmallow until the facilitator got back, they would be rewarded with an additional marshmallow. If they cracked, succumbed to temptation by eating the marshmallow before she returned, they would not be rewarded with an additional one.
We hid 2 cameras in the room to watch the hilarious results.