Predator-Prey Population Simulator
Watch rabbit and fox populations rise and fall with the Lotka-Volterra model.
About the Predator-Prey Population Simulator
Free predator-prey simulation. Change growth, predation and death rates and watch prey and predator populations cycle on a live time graph and phase plot. Built for biology, the predator-prey population simulator runs instantly in your browser: change a setting or drag an object and the result updates at once, so you learn by trying things out rather than only reading about them.
Watch rabbit and fox populations rise and fall with the Lotka-Volterra model. Use it to explore biology ideas at your own pace, then check what you found against the key ideas further down this page.
How to use the Predator-Prey Population Simulator
- Use the controls to change Prey birth rate, Predation rate, Predator gain from eating, Predator death rate, Starting rabbits, and more. The simulation reacts instantly.
- Press "Pause", "Restart" to start, reset or change what is happening.
- Where you see a glowing handle, object, weight or atom, drag it with your mouse or finger. Everything responds in real time.
- Watch the readouts and graphs update as you experiment, and compare what you see with the key ideas below.
Things to try
- Start with the defaults and watch the cycle.
- Raise the predation rate.
- Change the starting populations.
- Follow the phase plot.
Key ideas you can learn
- More prey means predators thrive, then more predators means prey crash, and the cycle repeats.
- The predator peak lags behind the prey peak.
- At the equilibrium point both populations would stay constant, but small changes start the cycle.
Where this is used in the real world
Ecologists and wildlife managers model predator and prey cycles for fisheries, forests and pest control, and the same maths describes epidemics and markets.
Who is this simulation for?
Biology students and teachers who want to explore living systems, populations and genetics interactively and safely.
For teachers: project it on the board, let students predict what will happen, then run it together. For students: change one thing at a time and write down what changes.
Frequently asked questions
Why do predator and prey populations cycle?
Prey growth feeds predator growth, then predators eat down the prey, then the predators starve, and the prey recover. The two populations chase each other in a loop.
Is the Lotka-Volterra model realistic?
It is a simplified model. Real ecosystems have limits like food supply and competition, but it captures the core lag between predator and prey.
Is the Predator-Prey Population Simulator free to use?
Yes. It is completely free, with no signup, no download and no ads inside the simulation. It runs in your web browser.
Does the Predator-Prey Population Simulator work on a phone or tablet?
Yes. It uses touch as well as the mouse, so you can drag objects with your finger. A larger screen makes the controls easier to see.