Final answer:
Omnivores are animals that consume both plant and animal foods. Examples include humans, bears, and chickens as vertebrates, and cockroaches and crayfish as invertebrates.
Step-by-step explanation:
Animals that have a diet including a variety of different foods from both plant and animal sources are called omnivores. Omnivores can range from vertebrates like humans, bears, and chickens, to invertebrates such as cockroaches and crayfish.
These animals have digestive systems that allow them to process both plant material and animal flesh. An interesting aspect of omnivores is that they can vary in their dietary preferences: some may consume more plant-based foods, while others may consume more animal-based foods, sometimes even seasonally.
A common example of this is the grizzly bear, which consumes more animals like fish during certain seasons and more plant foods like berries in others.