Adaptations favor the survival of animals and this may depend on their physical appearance and behavior. For example, whales have characteristics that help them live in water, such as the shape of their body that benefits them in swimming and they have small fins that help them move quickly in the water, while an eagle has wings for flying and fur to keep their claws warm and sharp for hunting (Kidport, 2012). Therefore, the whale is different in that it lives in the water compared to the eagle on land. This reinforces the idea that animals are different and are grouped in a way that suits their abilities and survival conditions. Food is also essential for all species, which categorizes them into three groups of nutrients they feed on, thus making it easier for scientists to group species. Animals can be carnivores, which allows them to obtain calories and energy by eating meat, like wolves. Herbivorous organisms eat plants as a source of energy and nutrients, for example horses. Omnivores are a collective group of animals that receive energy from both plants and animals, such as chickens. Therefore different living beings are exposed to hunting for different types of food (Burchhill,