Clare Pastore, age 10, of Rowayton, Connecticut, for her question:

Does the hyena really laugh?

Animals' voices seem to express their feelings but humans can't often tell what they mean. The hyena has a remarkable voice and he uses it to make several different announcements. When he finds the leftovers from the lion's banquet, he utters the weird sounds that remind people of a human laughter. Actually, it is more like a non human laugh    the sort of frantic cackle that we expect to hear when the movie monster captures the leading lady. This devilish, blood curdling giggle echoes over the African plains at night.

Certainly, this seems to be an expression of pleasure because he utters his famous hyena laugh only when he finds food. But we cannot be sure that it has the same meaning as human laughter has to us. At other times, he pauses now and then to utter a very different cry to the sky. It begins with a low, mournful howl that gradually climbs up and ends with a high, shrill shriek.