Children who wonder what it would be like to walk inside a whale should sign up to be at the Abington Library on Saturday at 2 p.m. Educator Cynde McInnis and her whalemobile will teach children about whales and their environment. As part of the program, children will be invited to walk inside Nile, a 43-foot-long inflatable humpback whale. Nile is based on a 25-year-old female humpback whale who often summers off the coast of Massachusetts. The event, paid for by the Friends of the Library, is for children entering kindergarten and older. Registration began Aug. 26.