Leave it to humans...if we can see no benefit to ourselves from an organism why, let's just kill it. Seemingly our way of thinking is that if we can't see that it has any immediate use to us then it's worthless, so why keep it around. Probably, since this was not a permanent nest,if left alone they would very soon have flown on their way; hopefully without a child or anyone else being stung. Pity...so sad. But a fabulous photo!

a side note to this was that I learned later that they hold onto each other while doing this. At first I thought it was a shirt or something thrown in the tree but that's ALL bees holding on to the next bee.