Animal structures refer to the physical features and body parts that make up an animal. These structures can include bones, muscles, skin, and organs, all of which work together to help the animal survive in its environment. For example, the skeleton provides support and shape, while muscles enable movement. Different animals have unique structures adapted to their lifestyles. For instance, birds have lightweight bones and feathers for flight, while fish possess fins and gills for swimming and breathing underwater. These adaptations help animals thrive in their specific habitats, showcasing the diversity of life on Earth.