A TRIP TO the National Zoo is turning into a cruel test for parents, an exercise in skill with euphemism and restraint of mordant humor. "Mommy, that doesn't look like a prairie dog." Well, no, it's a rat, honey, and he's sharing his underground house with the prairie dogs. (Just as the Serbs "shared" their houses with the Bosnians.) "Mommy, I'm tired of waiting for the dogs to come out. Can we go see those little red pandas?" Well, they're, uh, napping.

Perfect parents no doubt use the occasion for lessons about life cycles. Like Charlotte of "Charlotte's Web," they tell their young charges about Father Earth and Mother Time, or patiently explain what "languishing" means. But the rest of us, chilly and rushed, resort to more comforting half-truths. The giraffes' mommy and daddy? Well, they're napping too. Eventually investigators may determine how the rat problem got out of control, how the rat poison got in the panda cage, what the giraffe autopsy really showed. In the meantime, parents can steer their children to Amazonia, where it's harder to keep track of the fish and fowl and harder still to grow too attached to them.