Narnia to Mark Wimbish, age 8, of Charlotte, N.C., for his question:

Why does a fly rub its legs together?

From our point of view, the fly is a very dirty little creature. She lays eggs that become wriggly maggots. She whizzes around, landing on the garbage, in the kitchen and maybe on your nose. And her tiny feet carry germs from here to there. This is why we keep her outdoors, cover the trash and keep tight lids on the garbage cans. But from her point, the fly is a very neat little person. When she rubs her legs together, she is busy scraping the dust and dirt from her small body. But this does not scrape off her germs.