Create the food chain: Eagle // Deer // Wolf // Grass
Grass → Deer → Wolf → Eagle
Create the food chain: Grasshopper // Snake // Hawk // Frog // Grass
Grass → Grasshopper → Frog → Snake → Hawk
Create the food chain: Heron // Algae // Plankton // Eagle // Fish
Algae → Plankton → Fish → Heron → Eagle