Oh Deer
Please note: this game is from the "Project Wild" workbook, published by the Ontario Ministry of Natural Resources. But many thanks to Jane Maddin who posted it to the Guide Mailing List!
You divide the girls into two equal teams, and line them up facing each other about 25 feet apart. (I'm making an estimate in the distance, if this is too close together you'll know.)
One team are the deer, and the other team is the food, water, or shelter.
Each round the deer must decide whether they are hungry, thirsty or cold. If the deer are hungry they hold their stomachs, if they are thirsty they cup their hands and if they need shelter they hold their hands together over their heads (tented).
The other team of girls decides whether they are food, water or shelter and they make the same symbols. The deer turn back to the other girls, and on the count of three they turn around with their symbol showing and the food, water or shelter is making their symbol too (they decide as well what they'd like to be.)
The deer then run across the space and catch their food, water or shelter. Only one deer per person. If there are more deer that need water than there are ponds, then the deer die and stay on the side of the necessities. The deer that get what they need, reproduce and take their new deer with them back to the deer's team. After each round the number of deer is counted, and recorded.
Play the game about 10 times, so that the girls can see how the subsequent generations of deer are dependent on the numbers of the previous generation.