Organisms that consume leaves are called herbivores. These creatures vary in size and living habitat, but have special digestive systems and teeth to help them chew and digest tough, fibrous plant stems and leaves. Although they do not consume meat, herbivores are nevertheless important components of the food web.
Herbivores occupy the second level on the food web: just below them are autotrophs, which are organisms such as plants, fungi and some bacteria that make their own food, primarily through the process of photosynthesis. Herbivores classify as primary consumers, which means that they eat the organisms on the first tier of the food chain, which are mostly autotrophs. Above herbivores are carnivores, or organisms that consume other plants and animals for food. This group also includes omnivores, which are creatures that eat plant and animal matter. While some organisms can consume plant and animal matter, herbivores have digestive tracts and teeth that are specially equipped for diets comprised of vegetation. Most herbivores have dull, large, flat teeth. These teeth allow herbivores to chew through and break down tough plant material. Herbivores are found around the world, and include small species such as aphids, ants and other insects to gorillas, elephants, and other large mammals.