1. Feathers: Birds have feathers, which are highly modified scales that provide insulation, waterproofing, and the ability to fly. Bats, on the other hand, have fur, which is made of hair.
2. Wings: Birds have wings that are formed by their forelimbs, which are modified into long bones with flight feathers attached to them. Bats also have wings, but they are formed by their highly elongated fingers, which are covered with a membrane of skin.
3. Beaks: Birds have beaks, which are specialized mouthparts that are used for eating, grooming, and defense. Bats, on the other hand, have teeth, which they use for catching and chewing insects or other food.
4. Egg-laying: Birds lay eggs, which are fertilized internally and then incubated by the parents until they hatch. Bats, on the other hand, give birth to live young, which are born after a period of gestation inside the mother's body.
5. Warm-bloodedness: Birds and bats are both warm-blooded animals, which means that they can maintain a constant body temperature regardless of the temperature of their surroundings. However, birds typically have a higher body temperature than bats.
In summary, while bats are able to fly, they lack the defining characteristics of birds and therefore belong to a different taxonomic group. Bats are classified as mammals, specifically within the order Chiroptera, while birds belong to the class Aves.