An ecosystem refers to all the animals and plants that live together in one place and how they interact. Different ecosystems can exist close together and some animals belong to multiple ecosystems. All living things must be adapted to their environment in order to survive, such as seals having flippers, thick blubber, and other features to help them swim and stay warm in the water. Within an ecosystem, plants produce food, herbivores consume plants, carnivores consume other animals, and omnivores consume both plants and animals.