Here's why:

* Herbivores eat plants. Caterpillars are known for their appetite for leaves, flowers, and even fruits.

* Omnivores eat both plants and animals. Caterpillars don't typically eat animal matter.

* Carnivores eat only animals. Caterpillars don't hunt or consume other animals.

While there are some exceptions, like a few caterpillar species that are known to eat other insects, the vast majority of caterpillars are herbivores.