Ben Dillon, age 11, of Lowell, Mass., for his question:

HOW LARGE IS THE MONITOR LIZARD?

There are about 30 different species in the monitor lizard family. They range in size from the giant Komodo dragon that weighs 300 pounds and is 10 feet long down to the little guys that are only eight inches long and weigh less than a pound.

Monitors are Old World lizards that live in tropical and desert areas throughout Africa, in Asia from Arabia through southern China, and in the East Indies and Australia.

These lizards are sleek, fast runners with tapered heads, long necks, strong legs and long, powerful tails. Their mouths are similar to those of snakes. The long, forked tongue retracts into a sheath and the lower jaw unhinges, enabling the lizards to swallow large prey whole. They eat insects, birds and reptiles and their eggs, small mammals, including pigs, deer and carrion.

Although monitors are mostly terrestrial, some species also climb trees and are good swimmers.

Monitors are among the oldest living lizards. The are related to monasaurs which ranged up to 30 feet long and lived from 136 to 65 million years ago.