Predator-prey
relationship

Predator-prey relationships is a term from ecology. It is understood as the temporally changing ratio of the number of prey to the number of predators:
The more prey there are, the more predators find food. Now the number of prey decreases. As a result, the food decreases and so does the number of predators.
Now, for their part, the prey animals can recover again and the cycle begins anew.