In sixth grade my class took a field trip to the Headlands sand dunes. We had a picnic lunch and there were bees everywhere. When we asked the park ranger who was our guide why the bees were going after our turkey sandwiches she said, in the fall when the queen bee leaves the hive to mate, the rest of the hive lose their way and need protein. Now, when I was 13 that made sense. But when I repeated it on Labor Day to group of friends after our lunch was swarmed it didn't make as much sense. After a tiny bit of research, i.e. Google, I discovered what were called "meat bees." Meat bees are not bees, they are yellow jackets. And yellowjackets are actually a type of wasp. Yellowjackets feed on sweet liquids and don't eat meat themselves, but they do collect meat to feed their larva. Mystery solved.