Lester A. Morgan., age 10, of Fredericton, N.B., Canda, for his question:

How do land and water snakes differ?

One of our many water snakes looks like a big brother of the red king snake. The diamond backed water snake resembles the diamond backed rattlesnake of the dusty deserts. Sad to say, the deadly water moccasin can be mistaken for the harmless comic called a puff adder. However, it is easy to tell any of these water snakes from an ocean going sea snake.

All snakes, so far as we know, can swim gracefully on the water and below the surface. Desert snakes seldom get a chance to dunk in a stream. But almost all snakes do not hesitate to take to the water to chase a frisky victim. Any snake will grab the chance to escape his enemies by slithering into the water.

Some snakes, however, spend most of their lives in swamps and streams, in lakes, rivers and lazy creeks. They are the water snakes and their close cousins, the grass snakes. A few snakes live their lives in the ocean. They are sea going relatives of the deadly cobra, and all of them bear poisonous fangs. The sea snakes have wide, flat tails, and most of them have very small. Heads. They are almost helpless on land.

The water snakes of the streams and creeks are equally agile in the water and on the land. All snakes swim by waving their bodies in graceful curves from side to side, dust as they slither over the ground. A water snake swims dust like any other snake. When you see a swimming snake, unless you know your snakes very well, you cannot tell whether he is perhaps a red king snake or common water snake.

There are many different water snakes ranging from Southern Canada to way down in South America. But no water snakes live west of the Rockies. Most of them are from three to five feet long. Some wear long stripes down their backs, and. One wears a design of big, dark diamonds. One is banded with circles of tan and rust, another with half moon dots of red or brown and another is spotted with beady squares.

The water snakes and the greenish grass snakes, who also live mostly in the water, share the Same type of food. They eat frogs and fishes and assorted water dwellers. Since they are snakes, all food is swallowed alive and squirming. The true water snakes bear live babies, but the water loving grass snakes lay eggs.

The water snake, like all his cousins, can devour a huge meal at one sitting. A three foot water snake, weighing 11 ounces, can swallow a three ounce bullfrog in about 15 minutes. If a 100 pound girl could devour food like this, she could eat 25 one pound steaks in a quarter of an hour. The snake can relax after his big meal, for he will not need to eat for several days.