Michael Devereaux, age 10, of Florissant, Mo., for his question:

Why is a polar bear white?

Many animals of the Arctic wear brown coats in the summer and change to white clothing for the long winter months. Some are hunters and others are the hunted. The bunny has to escape the fox, which must sneak up on his victim without being seen. For this reason both the hunter and the hunted have coats to match their backgrounds. In winter the snow changes the brownish Earth to white, and the northern animals change the colors of their coats.

The big polar bear spends all his life in the ice bound snow covered Arctic. He lives in a white world, and to stay alive he must catch himself plenty of meaty food. If he wore brown, his victims would see him coming from afar and have time to escape. Such a bear would soon starve. But the polar bear is not noticeable against his white background of snow and ice.