Move the desks to the side of the classroom to create an open, clear area. Explain that their prey is one on the index cards. Instruct the students to carefully move around the cleared area collecting their prey. Ask the predators when it was easy to find prey and when it was difficult. Discuss what might happen if an ecosystem becomes overpopulated with predators or with prey.
Ecosystems strive for balance.
An increase of prey animals can result in an increase in predator populations. Conversely, a decline in prey animals can result in the decline of predator animals. In New Jersey, an example of an unbalanced ecosystem is the population explosion of the white-tail deer.