Carnivores such as grass → hare → snake → eagle.
Grains → insects → frogs → snakes.
Big fish eat small fish, small fish eat shrimp, shrimp eat zooplankton, zooplankton eat green algae.
Food chain cannibalism (scavenger food chain). Refers to the food chain formed on the basis of bits and pieces. Such as leaf fragments and microalgae → shrimp (crab) → fish → fish-eating birds.
The parasitism of food chain is based on large animals, and small animals parasitize on large animals to form food chain. Such as mammals → fleas → protozoa → bacteria → viruses.
= = = = There should be only these three kinds for the time being.