This is an ecosystem with 3 different animals - rabbits, foxes, and lions, and one producer - grass. Foxes eat rabbits, and lions eat foxes and rabbits. Some things that this model can show is the decomposition when the animals die. When an animal dies, it leaves behind compost. You can also change the number of animals in the ecosystem with sliders. Some things the model cannot represent is the fact that it takes 2 animals to reproduce instead of 1, the water supply, human hunting, and the time that the animal is pregnant.