Eldonna Beal, age 9, of Spokane, Washington for her question:

Are birds mammals or reptiles?

There are about 9,000 different birds in the world    and none of them are related to any of the other animals. All of the mammals wear some sort of fur, even if it is just a few bristles. None of the other animals have fur. The reptiles have scaly skins. And the birds, all of the birds, wear feathers. None of the other animals have feathers. So if an animal has feathers, you may be sure he is a bird and not a furry mammal or a scaly reptile.

Most of the mammals and most of the reptiles have four legs. Butnone of the birds have more than two legs. Instead of front legs, orarms, they have wings, though some have wings too weak for flying. All the mammals feed their babies on mother's milk    but none of the other animals do this. Most of the reptiles lay soft shelled eggs. All of the birds lay hard shelled eggs. Some experts say that the distant ancestors