We've had a few problems with wasps around our feeder, but nothing like this. We filled the feeder this morning about 8:30 and it was empty by noon. I noticed a few bees around the feeder at first, but then they swarmed and all seemed to collect around only one of the four feeder outlets. Amazing! There would be so many stacked up that some would fall off and come right back for more. I personally have never seen anything like this.