One year while studying another of the themes of Sukkot / Sukkos - fragility of life and concern for her ecosystems - I gave permission to the children to invite one mystery guest to dine in the sukkah each night.
First they drew numbered slips from a bowl to determine whose turn would be first.
They would decorate a chair in the sukkah as a seat of honor for the guest. Part of learning and practicing the mitzvah of "hachnassat orchim" - welcoming of guests.