Is there a chance they are going into your walls, maybe beside the duct work? When I called the other day about eliminating a hornet nest in a shrub, the pest control place I called wanted $150 for the "initial treatment". I got the impression I was looking at $300. If they get into your walls, I can only imagine what that would cost.

Good Luck!

Yikes! I wouldn't know a Yellowjacket if I saw one. Aren't they a yellow and brownish red striped wasp? A good friend of mine was stung many years ago by one, that had a nest underground or something inher flower bed. She found out the hard way, that she was allergic to them. She had to be rushed to the emmergency room. She now carries Epinephren syringe in her purse at all times.

My husband found one underground next to one of our gardens. He poured gasoline in the hole and ran like H*LL! Got rid of 'em!

Thanks so much to all for your suggestions and solutions. The problem we had was in not knowing exactly where the hole was since it was under the H/A unit and not accessible. My husband wanted it gone yesterday,of course, so we called our termite company. He used a sprayer connected to his truck (and a lot of spray)which left a residual to deter them later and a 30 day guarantee. He said Sevin is good. The foam sprays are better for instant knock down but leave no lasting deterrent. The price he quoted was $125 but I reminded him about our termite contract and he knocked it down to $100.I am sure the "home remedies" would have worked but after getting stung already hubby wanted to take no chances.We will use those for future holes we can see.