Gr 4-6 For the most part, Ryden repeats the success that she had with Bobcat (1983) and America's Bald Eagle (1985, both Putnam). Her verbal pictures of beavers are enlightening, and many cases, endearing. Her image of the residents of a beaver lodge in midwinter, ``talking'' to each other in soft murmurs in the interior darkness, presents more clearly than the sharpest photographs how some native American tribes could believe beavers to be `little people.'' Her observations also dispel the mental pictures painted by the phrase ``busy as a beaver.'' Slow and steady does it, with plenty of breaks for dining, socializing, and grooming. It is here that a discrepancy creeps in. Ryden states that a beaver grooms and ``waterproofs'' his fur with ``oil. . .secreted from two glands located on each side of his mouth.'' Every other source consulted about grooming oil stated that the glands are anal glands with openings into the cloaca. The book is accompanied by many black-and-white photographs, mostly excellent, but at least one showing strong signs of retouching. Nevertheless, do send readers to Ryden's book for an interesting look at a mammal who, like man, sees the world as it is and changes it to suit himself. Patricia Manning, Eastchester Public Library, N.Y.