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| While we humans have one set of eyelids, birds have three.
The outer eyelids are just like ours, they close over to protect the eye completely from wind, rain, dirt and light.
The second eyelid closes over when the bird is sleeping.
The third eyelid is an almost see-through flap of skin that sweeps across from the corner to keep the eye clean and safe from wind and bright light. | |
| Feathers are made mostly of keratin, which is the same material as human hair and fingernails. They are strong, smooth and light, which makes them an ideal covering for animals that fly.
Birds have three kinds of feathers: down feathers to keep them warm, contour feathers to make them smooth and sleek, flight feathers in their wings and flight feathers in their tails to help them fly.
The feathers on a bird’s tail are particularly important when flying. Birds twist them in different directions to help steer, and they pull them down to act like a brake when landing.
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