Steve Murphy, age 10, of Kenwood, Calif., for his question:

DO WORMS HAVE EYES?

Surely the earthworm is one of nature's most remarkable small miracles. He has no legs, yet he can travel from here to there and dig himself a burrow. He is both a mother and a father; and when cut in half chances are he can regrow himself into two complete worms. Though he has no human type eyes, he can tell daylight from darkness and even detect the shadow of a hungry robin.

The earthworm has no eyes like those of the higher animals. But you can prove for yourself that he has some sort of vision. Take a flashlight and wait by his burrow in the dim light of early dawn or late evening. These are the times when he is most likely to crawl forth to forage for food. Wait until his head and the front end of his body emerge from his tunnel. Then turn on your flashlight.

Almost at once the little fellow stops and shrinks back into his dark burrow.  Obviously, he was able to detect your beam of light  and avoid it. He performs this impossible miracle with the help of special cells buried in his soft pink skin which are sensitive to light and attached to nerves that flash messages, ordering the worm to retreat from the light to a more shady region.

Most of his light sensitive cells are concentrated in the head and tail ends of his wormy body. This is where he needs them most, because the two ends of his body are more likely to be exposed above the ground. These remarkable cells are sensitive enough to detect moving patches of shadow, which explains how he can sense the presence of a hungry robin  often in time to make a getaway.

The earthworm has another important reason for avoiding the bright light of day. His soft pink skin tends to dry up and shrivel in warm sunny air  which is fatal. To survive he must stay moist, and his safest place is down in his dark burrow where the air is cool and damp.

    The earthworm also has taste cells to select favorite foods, and other cells that tell him about temperature changes. Though he has no ears, his skin has bundles of cells that sense vibrations. To him, footsteps must feel like shuddering earthquakes warning him to scoot back down to his burrow.