Andrew Fett, age 9, of Lansing, Michigan, for his question:

Which is the world's biggest spider?

Scientists have named almost 30,000 spiders. The tiniest ones are no bigger than pinheads, the giants are as big as a man's fist. Some of the biggies have smallish bodies and very long legs. Others have big bulky bodies and shortish legs. Many of the whoppers look bigger than they are because they wear fuzzy coats of rusty brown hair. These variations make it very difficult to judge the giant spider contest.

Experts may disagree about which is the champ. Others say that nobody knows because most of the world's spiders are shy characters who keep out of sight. In any case, we know about a whopping tarantula spider who lives in the tropical jungles of South America. The width of her legs and body is eight inches. Other leggy specimens are ten inches wide. The bird spider of South America has a body four inches wide, though his legs are rather short. He captures small birds in the treetops. Maybe this bird catcher or one of the giant tarantulas is the world's biggest spider    but nobody can be sure which one is the real champ.