An omnivore is an organism that regularly consumes a variety of material, including plants, animals, algae, and fungi. They range in size from tiny insects like ants to large creatures—like people.
Human beings are omnivores.
People eat plants, such as vegetables and fruits. We eat animals, cooked as meat or used for products like milk or eggs. We eat fungi such as mushrooms. We also eat algae, in the form of edible seaweeds such as nori, which are used to wrap sushi rolls, and sea lettuce, eaten in salads. Bears are omnivores, too. They eat plants like berries as well as mushroom fungi and animals like salmon or deer.
Omnivores are a major part of the food web, a description of which organisms eat which other organisms in the wild. Organisms in the food web are grouped into trophic, or nutritional, levels. There are three trophic levels. Autotrophs, organisms that produce their own food, are the first trophic level. These include plants and algae. Herbivores, organisms that consume plants and other autotrophs, are the second trophic level. Both omnivores and carnivores, meat eaters, are the third trophic level.
Autotrophs are called producers, because they produce their own food. Herbivores, carnivores, and omnivores are consumers. Herbivores are primary consumers. Carnivores and omnivores are secondary consumers.
Most birds are omnivores. Robins pull worms from the ground. They also feast on berries. Ostriches graze on plants and grasses. They also eat lizards and insects.
Many mammals are omnivorous. Skunks eat rodents, lizards, honeybees, leaves, grasses, nuts, fungi, and almost anything else they can find.
Some reptiles are also omnivorous. Box turtles feed on fish, frogs, rodents, and many other creatures, but they also eat flowers, berries, and roots.
Fish can also be omnivorous. The opaleye, a fish that feeds mostly on seaweeds along the Pacific Coast of North America, also eats small creatures found among the seaweed.
Some insects are omnivores. Ants eat seeds, nectar, and, often, other insects.
Some omnivores are scavengers, creatures that eat the meat of dead animals. Black bears eat mostly nuts, berries, and other fruit. But if they find a dead animal, they eat it.
Many animals that are often thought of as carnivores are in fact omnivores. Red foxes, for example, prey on rabbits, but they also eat fruit.
Some animals that are thought of as herbivores also eat animals. Squirrels eat mostly nuts, fruits, and seeds, but they sometimes eat insects, small birds, and other creatures.