Living things need resources such as water, food, light and space. When several need the same limited supply, one can leave less available for another. That is competition. In this model the users have equal needs. Adding more users without adding supply reduces the amount available per user; it does not make a bigger supply appear.
Plants, animals and ecosystems · Discover & try
What happens when living things share a limited resource?
Reading level 1 of 5 · EarlyChange
Word help
resource
Something an organism uses, such as water, food or space.
competition
Reduced access when users require overlapping limited resources.
Watch · Try · Explain
See how it works
The interactive activity is loading.
Equal-user resource tokens; shares are bookkeeping, not real growth, survival or carrying-capacity predictions.
What to look for
- The resource total is conserved
- Supply and demand are separate
- Real organisms need not share equally
Explain what you noticed
Two lizards and then four lizards share the same limited insect supply. What new pressure is plausible?
Keep this idea: Demand can grow without the available supply growing.
Follow the sources
- Smithsonian Learning Lab — Interdependent Relationships in Ecosystems
- Smithsonian research repository — Living Close to Your Neighbors: Competition and Facilitation
Source material checked 2026-10-28. Explanations and activities by Nepedia. Source links do not imply endorsement.
Keep following the idea
Next discovery →