The difference between a dirty rat and a man who's a mouse is enormous, the difference between a rat and a mouse in reality simply a matter of size; so there's justification for lumping them together, then separating the marauders who live on man from the denizens of field and forest, as this compendium does. But the organization of the first third is so loose, the statements so generalized, that the reader has difficulty determining just what distinctions are being made. Furthermore, some are unexplained (e.g. why rats are more intelligent, why mice are more timid). The chief drawback of the book as a young juvenile, however, is the paucity of illustration; very few of the types described are drawn, and such aspects of behavior as the lodges of the wood rats, which may reach five or six feet, beg for pictorialization. Information, then, on rats and mice in history, in in legends and literature, as found throughout the world, as pets and as laboratory specimens--for use where necessary since there's nothing similarly comprehensive. But it's not tempting as bait or satisfying as a study.