1. There are prey and predator populations in the model. The population size can be adjusted by the "number-of-prey" and "number-of-predators" sliders. Once the user sets up the population sizes, they remain stable over time. There are three pairs of predator-prey relationships to try.

2. Each predator will hunt five times each tick. It has to get two successful hunts to survive. In each hunt, users may or may not allow the predators to identify the slowest prey in their hunting range. When "spot-the-slowest-prey" is off, the predator randomly picks one prey. It kills the prey if its speed is higher than that of the prey. When "spot-the-slowest-prey" is on, the predator picks the slowest prey. It kills the prey if its speed is higher than that of this prey.

3. The prey only dies when it is preyed on by the predators.

4. In each tick, both populations are re-established based on the survivors. The speed of new prey and predators are around the average speed of the survivors, with some variations determined by the relevant speed mutation.

5. Mutation of speed for prey or predator can be controlled by the relevant sliders. Note it does not determine the mutation direction but only represents the extent to which the offspring can mutate. So the mutation can lead to either a faster or a slower runner.

6. Users may add faster or slow prey/predators into the simulation, which are either slower or faster than the min/max speed of the existing prey/predators.

7. This simulation does not consider the energy cost of prey or predators. The hunting success is solely determined by speed difference.