Ruth Leidhecker, age 9, of Williamsport, Pennsylvania, for her question:

Do dolphins migrate?

Most of the dolphins stay in their favorite warm or fairly warm seas. They are great swimmers, very playful and very fond of fish. And dolphins like other dolphins. They hunt and play together in large groups. Sometimes they chase the fish up the rivers and sometimes they chase them far out to sea. But so far as we know, they do not migrate for thousands of miles, regularly every year.

The chubby dolphins are about eight or ten feet long and to us they seem like giants. But actually they are small cousins of the whopping whales. And some of the whales migrate thousands of miles every year. Humpback whales migrate between Australia and the south polar seas around Antarctica. The great grey whales spend the summer in the north polar Arctic Sea. Come fall, the stately procession swims far southward along the coast of California. In spring they migrate back to the Arctic.