Steve Giddens, age 11, of Warrenton, Georgia, for his question:

What are sand rats?

The ratty rodents belong to a huge clan and their assorted members inhabit every liveable part of the world. The sand rats, alias the gerbils, are found in parts of Asia and Africa where the climate is warm and dry. In size, they are a little too big to be called mice and a little too small to be called rats. As a rule, they enjoy life in sandy regions where there is just enough moisture to support a scanty sprinkling of grasses and small bushes. Sand rats are great burrowers who feed on underground roots and come out only at night to gather helpings of weedy seeds.

Around cultivated areas, the sand rat is rated as a serious pest. He devours the roots of crops and steals grain seeds to store in his underground pantry. In 1878, a swarm of sand rats in India destroyed all the crops through 8,000 square miles. What's more, the wretched rodent often has fleas that carry a dangerous plague. Wherever he lives, the sand rat must be rated as a serious enemy to mankind.