When they abscond there is a lot if bees in tight area causing a loud sound and probably some type of pheromone release. They do not immediately fly to tree often landing on hives close by. This causes the other hives to become alerted and they start to react. The whole apiary starts to take notice and it becomes very loud. Several hives can take flight. For me yesterday I saw 3 empty out as this was occurring. Years ago I did a lot of cut outs and cut outs are prone to absconding. I had 10 large health hives abscond on the same day. With all the activity and empty hives robbing starts and this can spread quickly causing more hives to fight and possibly abscond. Boxing them in the same location seems to aggravate this because hive continue to roar for hours, often absconding again. Some bees go in the wrong hive aggravating other hives.