There are three principal kinds of animal diets. In a carnivorous diet, animals feed on other animals. Most fish are carnivorous. So too are owls, snakes, and wolves. On an herbivorous diet, animals subsist on plant food. Cattle, Japanese beetles, seed-eating birds, and plant lice are among the many herbivores. With the omnivorous diet, animals have a mixed diet. They feed on both vegetable and animal matter, dead or alive. Many kinds of worms, crabs, lobsters, insects, bears and raccoons are omnivorous. humans are also omnivores.