The students must divide into four groups and line up behind each other.
The exercise has a time limit of one minute. Before the timer runs out, every member from each group , must walk up and grab some food (the circles). Once the first group has gotten their food the second group will do the same.
As the timer continues it is now the next groups turn to get their food. However, the timer ran out before all of them could get a piece.
The exercise starts over. The students will then start again and try to collect food.
Once the minute is over and the food is all gone that means the growing season has ended. Those with 1 or less pieces of food couldn't make it through the winter so they died.
Finally ,explain what happens when students were limited on time, and were in competition with others to gain food. Result: there wasn't enough food for all the animals to survive the winter. That is what carrying capacity is, the maximum amount of support an environment can give. In this example it couldn't give enough food.