Do yellow jackets and bumble bees compete for territory?

Yes, I have noticed that bumble bees and yellow jackets DO compete for territory. I have had many yellow jackets infesting my home in upstate New York each season for 17 years. However, this last summer, I had a bumble bee family that moved into my front porch. I watched them each day as they literally chased away the yellow jackets whenever they came near. Yet the bumble bees never caused any harm to me or my family. Thank goodness for my "watch dogs", the bumble bees -- they are my guardians against those angry yellow jackets!