Already a favorite of preschoolers, Fleming (In the Small, Small Pond, 1993, etc.) takes an appreciation of the natural world a giant step further. Rhythmic verse--""Where once there was a wood/a meadow/and a creek . . . sit houses side by side/twenty houses deep""--demonstrates that there was another sort of community before people arrived, ""where once the brown snake/slithered and slipped out of sight."" An ecology lesson it surely is, but it's also a celebration of the earth and its creatures. Illustrations in vivid jewel-and-earth tones appear on handmade paper; the woods, creeks, and meadows are clean and inviting, and, bringing balance to the presentation, the new houses are not without their charms. The lively back matter, titled ""Welcome Wildlife to Your Backyard Habitat,"" offers substantial, easily executed suggestions for encouraging wildlife around the home; it's information just right for family and classroom sharing. Perfect for Earth Day observances, a book that's as welcome as spring.