What is the one thing that really makes a bird different from other animals?
The one thing that really makes a bird different from other animals is the presence of feathers. Feathers are a unique feature of birds, and they serve several important functions, such as providing insulation, allowing for flight, and aiding in camouflage and display. Feathers are made up of a protein called keratin, which is the same material that makes up human hair and nails. They are lightweight, yet strong and flexible, and they come in a wide variety of colors and patterns. Birds molt their feathers regularly, usually once or twice a year, to replace old and worn feathers with new ones.