I would highly recommend Jerry the Bee Guy, (206) 331-1051. Poison-free per his card. Marvin of JBG is the bee guy.
He took care of the little buggers that made their way into my attic just outside of my front door last summer. A huge nest. He gave me great info on what they were doing, damage they were NOT doing (to my house) and safety issues with this species and others that he looked carefully for about my property.
His rates were quite reasonable, he responded quickly to my frantic call and was at my house within 2 days during the busy summer season.
Watching the hundreds of bees that covered his bee-suit once he urged them out of my attic (no chemicals, just smoke and bee-talk) made me very thankful I had called him.
Good luck!