Jason Snyder, age 9, of Baton Rouge, La., for his question:
ARE THERE MANY KINDS OF SNAILS?
There are more than 80,000 kinds of snails on earth. Some are so small that one wouldn't even cover the head of a pin while others grow to be about 2 feet long.
You'll find snails just about everywhere. Some live in deep forests while others like dry deserts. Others are found only in rivers, ponds and lakes. All parts of the ocean have snails, too.
Snails eat many kinds of food. Some that live on land eat rotting plants. Snails that live in lakes or rivers feed on water plants or dead animals. Some ocean snails feed on seaweeds while others eat sea animals.
A few ocean snails are parasites and live in the flesh of starfish or inside living sea animals called corals.
Some snails live for two years while other kinds may live as long as 20 years.
Many snails are an important food for fish and birds. And lots of people eat a type of garden snail known as escargot. They consider it to be a great delicacy. In pronouncing the word, the "t" at the end is silent: es car go. Other types of snails are considered pests to the farmer and to the person with a backyard garden.
Snails creep along on a strong muscular organ called a foot. Its body has a head with tentacles or feelers, eyes, a mouth and tiny teeth. Most are covered with coiled shells although some types go without this covering.
There are three main groups of snails: land snails, fresh water snails and salt water snails.
Most land snails are found in shady, damp places, such as under logs or stones. Most live on the ground but some are found in trees. Most land snails have lungs. There are about 20,000 kinds of land snails.
About 5,000 kinds of fresh water snails are found in rivers, ponds and lakes. There are about 55,000 kinds of salt water snails and they live in all parts of the world's oceans. Most of the water snails have gills that take oxygen from the water.
A moving land snail pours out a sticky liquid called mucus, which serves as a path. The snail's enemies, beetles and ants, sometimes get caught in the mucus.
During dry weather, the snail seals itself inside its shell with a "door" of dried mucus, called an "epiphragm." It rests in this inactive condition, called "estivation," until the dry spell ends.
Snails that live on land have both male and female sex organs in the same animal. Most of those that live in water are either male or female.
Certain fresh water snails of the tropics carry schistosomiasis, a disease that causes thousands of deaths each year.
The giant African snail destroys flowers, vegetables and young rubber plants. This large snail is about 6 inches long. Although it is native to Africa, it is now also found in Hawaii and the Miami area of Florida.