Like robins, and snowdrops, Girl Scout cookies are harbingers of spring, and these Junior Girl Scouts from Troop 47027 at Willard School were out on Central Street on March 8 enthusiastically hailing customers. The Girl Scout Cookie Program, the largest girl-led entrepreneurship program in the world, comes around only once a year for six to eight weeks, with its perennial favorites – Trefoils, Thin Mints, Do-Si-Dos and Lemonades – as well as gluten-free Toffee-tastic and Caramel Chocolate Chip.