Phenomena: - National Geographic

via brain teasers - Google News http://news.google.com/news/url?sa=t&fd=R&usg=AFQjCNH79Wi-cn9ntpCoM2SqyOtM5BrVdw&url=http://phenomena.nationalgeographic.com/2013/03/20/swarm-shoal-flock-hive-brain/