All Activities
Science

Food Webs

Overview

Students build a food web from multiple food chains and investigate how removing one species affects the whole system.

Learning Objective
Students understand that ecosystems contain interconnected food chains and can predict the effects of removing one species.

Resources needed

  • Cards or slips of paper with species names written on them
  • String or wool to connect them

Lesson stages

0 / 7 done
  1. 1 Recap food chains: grass → grasshopper → frog → snake → eagle.
  2. 2 Introduce a second chain that shares species: grass → mouse → snake → eagle.
  3. 3 Connect both chains — they share grass, snake, and eagle. This makes a web.
  4. 4 Each student holds a species card. String connects every species that eats another.
  5. 5 Pull the grass card — everyone connected feels the tug.
  6. 6 Remove the frog species — what happens to snakes? To eagles?
  7. 7 Discuss: why is biodiversity important for ecosystem stability?

Tap a step to mark it as done.

Variations

  • Use locally familiar species to build the web.
  • Add a decomposer — show that decomposers connect all chains by breaking down dead matter.
  • Introduce an invasive species — what disruption does it cause?
More information

Teach: food web, interdependence, species, ecosystem, producer, consumer, decomposer. The physical string activity makes interdependence tangible — the web is literally felt.

Build the web as a class before asking individuals to predict what happens when a species is removed.

Can students predict the cascading effects of removing one species from a food web? Can they explain why a food web is more stable than a single food chain?

Write species names on leaves or stones instead of cards. Use any available string, strips of cloth, or vines to show connections.

Students often think removing one species only affects its direct predator and prey. The web activity demonstrates cascading effects — changes ripple through the whole system in unexpected ways.

Food webs are a central concept in ecology. Understanding them explains why biodiversity matters — more connections mean greater ecosystem resilience when one species is lost.

Activity details
Primary Medium 25 minutes 5 minutes prep Small Group, Whole Class Indoor & Outdoor
Topics
Food Webs Ecosystems Interdependence