We recently saw an interesting event. A swarm of bees approached an existing hive that has for years been living in the peak of the house (I know -- we should have the hive taken out of the house but that's a long story). The swarm flew over to the house and seemed to attack the hive. We watched the bees as they appeared to fight in the sky -- many bees fell down and landed on the roof of the house but then later recovered and started flying again. Eventually everything settled down. The hive still has bees and still seems happy and active. We'd like to better understand what happened though -- was this really two separate groups fighting for the hive? Thanks for any info!