Kris Phillips, age 12, of Bethel Park, Penn., for his question:

WHAT IS A BARNACLE?

A barnacle is a salt water shellfish that fastens itself to objects under water. You'll find barnacles on wharf piles, rocks, turtles, ship bottoms and even whales.

 Marine engineers have spent a lot of time trying to find ways to prevent barnacles from attaching themselves to wharves and ships.

When first hatched, a barnacle is a small creature with six pairs of legs and one eye. He can swim from birth and looks a bit like a tiny water flea.

In his next stage the barnacle has 12 pairs of legs, two additional eyes and two large feelers. In his third stage he has 24 legs but loses his eyes. The adult barnacle attaches himself to some object for the rest of his life as he forms a hard, limelike box around himself. It eats microscopic plants and animals.