Glen Overton, age 10, of Milford, Conn., for his question:

WHAT EXACTLY ARE SILVERFISH?

His grayish body does not shine like silver, and certainly the whiskery little silverfish is not a fish. He is a land dwelling insect, and his ancestors were scooting around in the days of the dinosaurs. In fact, his remote ancestors wer here on earth 400 million years ago.

Scientists classify him with the bristletails, shy little gray insects who do their best to keep out of sight. They are called primitive insects because none of them has wings and none of them goes through the miraculous change from caterpillar to butterfly. The average silverfish lives in the woods, and we never catch a glimpse of him.

However, sometimes silverfish take up residence in human homes  and get themselves rated as pests. They cannot abide the light of day or even a sudden flashlight. For this reason their homes are in dark crevices, perhaps in the walls or under the floors. They also like moist conditions, and their favorite hideaways are under the sink.

There the female silverfish lays her tiny eggs. The eggs hatch and become mini copies of their parents. As they grow, their skins become too tight. Meantime, new skins grow underneath and when all is ready the old skins split apart. The growing silverfishes step out and enjoy the comfort of their larger outfits  for a while.. As they grow bigger, they shed several old skins for larger ones.

A silverfish is born hungry and continues to be hungry throughout his life. His favorite food is starchy stuff, such as cake crumbs and crusts of bread. He even makes a meal of the paste on the back of the wallpaper.

This sort of food is plentiful in the average kitchen. However, since the silverfish cannot abide light, his foraging is limited to the darkness of night  when the family has gone to bed. This is when he scuttles out from his secret hideaway and prowls around the kitchen. If you suspect that he is there, tiptoe quietly in the dark and suddenly switch on the light. And watch him scoot away home    his slim gray body is covered with dusty scales. Being an insect, he has six legs. There are long whiskery antennas on his hungry little head, and there are more spiky whiskers on his tail. Though he does not do a great deal of harm, he is rated as a household pest and naturally we want to rout him out of our walls and floors.