How old is your queen? The older she is the more she's itching to swarm. Feeding them may have been the triggering mechanism but they were already set up to swarm if they did it only 3 days after you started feeding. If you've got that much room and 1/2 the population just flew off consider reducing the hive in size (and entrance) so they have less to defend. If you captured either of the swarms put them in the removed box(s). On the bright side, you should end up with a fresh queen for next year in the hive the swarms eminated from.
I would seriously consider feeding the respective hives to get them built up with populations and stores that will survive the winter. That is unless you're planning on combining these before winter sets in. Considering all the heat and dry weather, if it was me I'd feeding.
I would seriously consider feeding the respective hives to get them built up with populations and stores that will survive the winter. That is unless you're planning on combining these before winter sets in. Considering all the heat and dry weather, if it was me I'd feeding.
