Elizabeth Murray, age 11, of Toronto, Ontario, Canada, for her question.

Is an earthworm male or female?

In the animal world of nature, all sorts of strange things are possible. Even so, it is somewhat hard to believe that the earthworm is both male female, so to speak. Nevertheless, it is true that the average earthworm becomes a mother and a father at the same time. Any two earthworms can mate, and each one fertilizes the eggs of the other. They go their separate ways, and each produces a sac of eggs, which is left to hatch in the warm, moist ground.

If baby earthworms knew who their parents were, the family relationships might throw them into a tizzy. The mother of one brood is the father of another brood. The mother of this second brood is also the father of the first brood. What's more, all the brothers in each brood also are sisters. And the sisters, naturally, also are brothers. All this family confusion occurs because every earthworm is both a male and a female.