And to this day, we carry our load...

Once upon a time, every bumble bee carried two buckets of honey to their hives. One day, a bad human wacked the Bee hive so hard that all the honey poured to the ground and was eaten up by that annoying winnie the pooh. The Queen bee, extremely angry with human civilization and their destruction of all the hard work done by the humble bees commented, 'those humans think they can get away with everything, don't they? Lets see how they deal with carrying TWO loads their whole lives.' And there was a revolution amongst the bees where they poked every human twice. And hence, our buttocks.