Kevin Bartoff, age 7, of Missoula, Mont., for his question:

HOW MANY KINDS OF ANIMALS ARE THERE?

Scientists have classified almost a million kinds of animals. There are more than 800,000 kinds of insects, which make up by far the largest group of animals.

There are more than 30,000 kinds of fishes, over 9,000 kinds of birds, about 6,000 kinds of reptiles, about 3,000 kinds of amphibians and about 5,000 kinds of mammals.

The scientists divide all living things into two main groups: the animal kingdom and the vegetable kingdom. Most animals move around, but most plants are held to the ground by roots. Animals eat plants or other animals.

The huge blue whale is much bigger than the elephant, which is the biggest land animal, or the giraffe, which is the tallest of all animals.

The variety of animal life is almost endless. Animals range from simple, one celled creatures, such as the protozoans, to complex, manlike apes, such as gibbons.