The blackberry bloom is drawing to a close. The country bees have a bit of time to wait until the Japanese knotweed blooms. Sometimes when there is dearth of nectar, a strong hive will try to rob a weak hive of their honey stores. The robbers will kill the queen and then plunder a hive if they can. We had our first robbing incident of the year in our Carnation apiary. The farmer noticed bees balling each other (fighting) on the front porch of a hive and called us. We reduced the size of the entrance so that the hive had less area to defend. Sometimes, bees can get into an all out war. I have not seen it but on two occasions our hive hosts have reported large numbers of bees fighting in the air in front of a hive. When we show up, we see large numbers of dead and dying bees in front of the attacked hive.
The bees have stopped swarming (I hope) and are now concentrating on building up lots of honey storage. Robbing is just one of the ways that bees try to collect honey. For the beekeeper, it is not good because the robbers can kill a hive.