Balanced, compactly built Rat Terriers are tough but elegant-looking. There are two size divisions: Miniatures stand 10 to 13 inches at the shoulder; standards are over 13 inches and as high as 18 inches. The smooth, shiny coat comes in varieties of pied patterns. (Pied, a word borrowed from the horseman’s lexicon, means “comparatively large patches of one or more colors in combination with white.”) These smoothly muscled exterminators are constructed for the efficient movement required for a long day’s work (aakc.org).