The Caterpillar Lab, from Keene, NH, will come to the Arnold Arboretum for 5 days of fascinating exhibits that are free and amazing for all ages:  10AM-5PM daily, August 22-26, in the Arboretum’s Hunnewell Visitor Center (map). There will be live caterpillars, cocoons, hatched eggs, shed skins, and much more. The Caterpillar Lab was founded by Newton’s own Sam Jaffe, who became enthralled with nature while exploring Cold Spring Park. For more information, email arbweb@arnarb.harvard.edu or call 617-384-5209.