Roseanne Brown, age 8, of Santa Rosa, Calif., for her question:

HOW LARGE CAN A COOT GROW?

A coot is a dark gray water bird that looks very much like a duck. It is also called the mud hen. The name "coot" is also used for about six kinds of wild ducks.

The American coot grows to be between 13 and 16 inches long. It weighs about one pound. The European coot is just a bit smaller.

The American coot lives in southern Canada, the United States, Mexico and South America. The European coot is also sometimes seen in parts of North America.

Most of the coot's body is dark with a white patch under the tail.

The bird has large, clumsy feet that have lobes or scallops for swimming.

The expression "silly as a coot" probably comes from the fact that the bird is known for its clumsiness. It can easily trip over its own feet.