Sylvia Foehner, age 13, of Winslow, Ariz., for her question:

Where did the Mexican jumping bean originate?

This fat little three-cornered bean comes from a bushy member of the spurge plant family. The plant is a native of central and South America, where it manages to make a living in several hot, dry, desert regions. It shares its world with a certain moth that resembles our pesky gypsy moth. When the bean plant blooms, the moth lays her eggs in the flowers. As the flowers fade, the eggs hatch into grubby larvae and remain inside the ripening seeds.

The grub inside each bean has plenty of food, but from time to time it must exercise. When it jerks and stretches its wormy body, the bean wobbles and Sometimes jumps. These astonishing jumping beans originated south of the border, and many of them actually come from Mexico.