WHITEFOOT MOUSE

Though the whitefoot mice play, nest and bear young (but don't mate) against backgrounds of evergreen branches and clumps of grass, Sullivan candidly acknowledges that his photos come from the laboratory--as does his rather clinical overview of whitefoot behavior which introduces concepts like ""biological clock,"" the dispersal of juvenile mice, the ""carrying capacity"" of a territory and hormone-regulated activity. Good enough, but the science-oriented youngsters who'll want these vocabulary-boosting observations are likely to find the mouseling portraits babyish.