Linda Sue Paulson, age 13, of San Bernardino, Calif., for her question:

How big is the biggest of the rodents?

The biggest of the rodents is about as large as a pig. He is built somewhat like a chunky pig and looks for all the world like an overgrown guinea pig. He is, in fact, a close relative of the guinea pigs. This giant of the rodent clan is the capybara of South America.

His body may be four feet long and stand about 21 inches high at shoulder level. He has no tail worth mentioning, and his hind legs are slightly longer than his front legs. A full grown capybara, most likely weighing more than you do, as a rule tips the scales at around 120 pounds.