Here's why:
* Trophic levels describe the position an organism occupies in a food chain or food web.
* Producers (like plants) make their own food through photosynthesis and are at the first trophic level.
* Primary consumers eat producers. This means herbivores, animals that eat plants, are at the second trophic level.
* Secondary consumers eat primary consumers, and tertiary consumers eat secondary consumers, and so on.