Birds are vertebrates. Their bodies have feathers, which keep them warm and waterproof. Birds usually have different kinds of feathers. One is for warmth and one is for waterproofing. Birds breathe oxygen. They usually eat fish, insects, worms and plants. There are birds on every continent of the world. Some birds do not fly but use their wings so they can move through the water. Some birds are so large that they are the same size as people. Some scientists believe dinosaurs evolved into birds.
Birds get their food in many ways. If they are trying to eat worms, they will peck around at the ground until they find one or if they see one on the dirt, they will pick it up. Some birds like fish. To get fish to eat, they will land on the water if they see some fish, and then they will usually jab their neck and mouth under the water to try and bite the fish.