A concrete illustration of a food web structure breaks it down into an understandable format that children can see and understand. Cut strips of green, brown, purple and red construction paper. Draw plants on the green, insects on the brown, herbivores or plant eaters on the purple and carnivores or meat eaters on the red. Create a paper chain that links the plants and animals in a sequential food chain. Join separate chains at points of commonality to show the food web relationships. Attach all the ends to the sun to show that all life depends on the sun for energy.
A living food web game gets children moving and helps them understand the impact of breaking a link. Choose a particular habitat and make a set of cards listing the plants and animals that live in that environment and depend on one another. Make enough cards for the entire class and include multiples of both predators and prey for a representative population of each species but only one example of the top consumer. Pass out the cards randomly to assign each child a role. Gather the class in a large open area and have them spread out. Hand one end of a ball of string to the top consumer. Ask her to identify her prey and pass the ball of string to anyone holding that card. Each child should grasp the string with one hand and unroll the ball to pass it around. Continue identifying prey and passing the string, keeping the web taut, until everyone is in the web at least once. Pose scenarios such as "an invasive species is introduced into the habitat which decimates the frog population." Everyone who holds a frog card drops the string. Point out that anything that eats frogs now has a reduced food source and is vulnerable to dying off or moving away because of one broken link. All frog predators would then drop their string and then their predators and so on in a cascading chain reaction. Discuss the significance of breaking even one link in a food web.
Let children create a cooperative bulletin board that illustrates the food web in the biome you are studying. Cover the board with a backdrop and put up a yellow sun. Brainstorm a list of plants and animals native to that habitat and assign one to each child. She makes a paper cutout or drawing of the plant or animal and attaches it to the bulletin board to create a scene of life in that environment. Loop yarn around thumbtacks to run a web from producers to consumers, prey to predator and show the relationships within the habitat. Alternately, you can draw or staple arrows between the creatures to diagram the flow of energy.
Technology in the classroom gives children an engaging way to share what they have learned while learning important technological skills for their future workplace. Using a digital presentation program such as Kid Pix or PowerPoint, children can create a slideshow that describes in detail the relationships in a food web. The presentation should identify the habitat and label the producers, consumers, predators, prey and decomposers within that system.
Reinforce the concepts you are teaching in science class during computer time by assigning online food web games. Harcourt School and Scholastic are just two of the many websites that offer free educational games that allow children to practice designing food webs in a variety of different habitats.