1) Choose what kind of habitat your ecosystem will be in such as a rain forest, a desert, a pond, or the ocean. 2) Assign each type of object a role such as a plant, a carnivorous mammal, an insect‐eating lizard, or a seed‐eating bird, that are appropriate to your chosen habitat. 3) Using your piece of paper as a habitat, select individuals of each type to go into your ecosystem. 4) Consider who eats what and whether each individual will have enough food when selecting your population sizes.