Dwayne Moehl, age 15, of Valparaiso, Ind., for his question:

WHAT IS A KILLER WHALE?

A killer whale isn't even a whale. A killer whale is the name of a large porpoise that can measure between 20 and 30 feet long and can weigh between three and 10 tons.

A killer whale has a glossy black back and a white underside. It has from 40 to 48 teeth with 10 to 12 on each side of each jaw.

Killer whales often travel in groups ranging from two to a dozen animals. It can swim at the rate of about 25 miles an hour, which equals the  fastest swimming whale, the blue whale.

Killer whales feed on salmon and other large fish, and sometimes attack smaller porpoises, seals and walruses. They have not been known to attack people.

The killer whale is found in all oceans, but especially in cold regions.