Strange English Plurals Leftover From a Bygone Age

A San Antonio, Texas, man says his six-year-old son wonders: If the plural of house is houses, why is the plural of mouse mice? And why is the plural of tooth teeth? These plurals are vestiges of a time when the middle vowel sound in some nouns changed to form the plural. Other old plural forms are reflected in such words as children and oxen. This is part of a complete episode.