Bees are drawn to white, especially bright white. That is why bee keepers paint the bee hives with bright white paint.
So funny! I always wondered why this particular bee kept bugging me. It was the size of a large flying black grape, I was in the middle of nowhere in Zion Nat Park trying to take a 5x7 image. Every time I went under the darkcloth the bee would zoom over and around me until I backed off away from the camera...the bee would then fly off towards some trees 30 feet away. Happened four times before I realized that I did not really need that image and packed up. And yep -- the darkcloth was bright white on the outside!
At least with LF landscape, a bad day of photography can be a good day of exercise.