Honeybee Democracy by Thomas Seeley is a fascinating account of how honeybee swarms make lilfe-or-death group decisions to move to a new location.  When the hive swarms they’ve made the decision to leave their current location, but don’t yet know where they will be moving to.  Scout bees are sent out to find possible locations for their new homes and then return to campaign for the places they have found.  They perform a “dance” which conveys such information as location, distance and conditions of the place they are advocating for, and the swarm must choose from the many different suggested places.  A great model for group decision making!