Sitting on her flowered bedspread at home in Northwest Washington, 8-year-old Macie McGraw cradles a pristine white beaver skull in her hands. She found it while hiking in Great Falls, Md., two years ago. After her family had the skull cleaned by a professional, it went on display in the "bones" section of the natural history museum that Macie has created on her bookshelf."There is one tooth missing," the second-grader mentions as she examines the skull. "I took it out for the 'teeth' section of my museum."Macie loves collecting and sorting natural things, and she sees herself as a naturalist and a curator. She started the museum when she was in kindergarten, displaying dead bees, cicadas, stink bugs and wasps. "Most people won't pick up a stink bug," Macie says. "But I've always liked how little bugs are so pretty and delicate. I like looking at different parts."