Ralph Cato, age 11, of Charlotte, N.C., for his question:

Do ANIMALS DREAM?

if animals have dreams, certainly they cannot tell us about them. However, in recent years, scientists have found ways to tell when a sleeping human is dreaming. It seems that the brain gives off different impulses called brain waves. The waves during a nondreaming period differ from those during a dreaming period. These differences can be measured with special instruments.

These same instruments have been used on certain sleeping animals. If their brain waves can be compared with those of humans, it seems that they, too, have periods of dreaming and of nondreaming.  In this case, cats and dogs have dreams, perhaps as we do. But there is no way to be sure whether they have nightmares or pleasant dreams.