Insects are like people, always looking for something, so if they are not doing any damage just leave them alone, if they start doing damage get some BT and spray them.

BT? What has that to do with wasps? Just curious as to your thinking, dangsr2.

Pat, no telling what the wasps are up to. Perhaps they are finding caterpillars and taking them away. Or moisture, or pollen.

BT or Bacillus thuringiensis,isnt that effective against moths and catepillars only?

you can kill yellow jackets by placing an inverted bowl over their underground dwelling. just put the bowl over the hole and make sure its firmly "somewhat" in the ground so no wasp can get out. the hive wont build an alternate exit and will starve to death.

most wasps wont sting unless you attack their nests, even swatting at most wasps wont induce attacks. and some are good predators for more damaging insects.

If the wasps aren't bothering you, why on earth would you want to spray them?
Wasps are good polinators.
They also eat some of the bad bugs!

I say leave them be!

I agree. I had a Giant hornet on my pepper plants. I have to admit, I have a slight phobia of bees, etc. so I was going to go "squish" but I thought about all of the good it might be doing eating all the bad little bugs, so I left it be. I've never seen a hornet like that in my life. It was a good inch to inch and a half, and almost all red in color. I've seen pictures of Giant Hornets, and European Hornets, I don't know for sure if it was those or not. I wish I'd taken a picture of it.

The Baldface hornets that were building a HUGE nest on the corner of my house had to go as it was right on the path that we take around the house. I have 4 kids ranging from 1 month to 8 years. I leave the nests in the peaks, and elsewhere, but when they build in a spot that could cause problems(Under my deck, corner of the house, etc.), they have to go. If it was just me, I'd ignore that area of the house till late fall, but I can't take the chance w/ my kids.

I don't know why they'd be so interested in sunflowers.

wasps like food too, a lot of animals like sunflowers for pollen and seeds. not to mention they are huge and easy to get at

Wasps are extremely fascinating to observe at close hand. I'll be enjoying a book outside in the spring, when wasps are building their nests, only to have them settle upon my book (while I am reading it) to take some paper away from the pages or even from the cover. Once they discover me, I can barely turn a page without disrupting their activity. The mud daubers are equally as interesting to watch, and I like to soak a bare spot on the soil just to watch them hard at work. They will light upon your arm to take advantage of perspiration or (if you're like me) a spray of sugar water.

But they are certainly pollen and nectar eaters. No small wonder that they find sun flowers interesting.