Yellow jacket hornets? I don't know if I'm familiar with those.

Up here we have yellow jacket wasps, and they are miserable, aggressive little buggers that will sting without provocation. They're even worse (positively psycho) in the fall when they have nothing to lose and are going after fruit and anything sweet and fermenty. There is no question of live and let live with these little monsters; they won't, so I don't either.

On the other hand, the bald-faced hornets we have up here are formidable but don't generally bother people unless their nests are threatened. Then, they are bloody dangerous.

There are other wasps such as paper wasps that only defend a threatened nest. Otherwise they leave you alone; and they are quite effective pollinators to boot.

Before taking out a yellowjacket wasp nest or a hornet nest, I try to thin their numbers down. A trap made from an 2-litre soda pop bottle with some sweet Coke (non diet) and ripe fruit in the bottom can catch hundreds if hung near their nest. I have seen several of these full to the brim near a hornet nest that was too close for comfort.

One year, we had an unbelievable explosion of yellow jacket wasps. It was a drought year, and birds and bees couldn't get anywhere near the bird baths that I keep filled no matter what. Every surface was literally encrusted with desperate wasps. So I got out my biggest shop vac and a 10-12 foot length of pipe and vacuumed up thousands and thousands. I tracked down a couple of big ground nests that were the source of most of them. In a damp year, I would just pour a cup of white gas down the hole, wait for a fuel-air mix, and throw in a flaming torch (whump! fixed). But the drought made that far too dangerous, so I carefully put an even longer pipe next to their hole and connected the shop vac. It ran all day, and across the yard I could hear the rattle of the little buggers bouncing down the pipe. At dusk, I pulled the pipe in and sucked up a cup of straight bleach. Problem solved.

For late season nests, I wait for a morning where there's a light frost and they can't really move. I knock the whole works into a garbage bin with a tight lid and let the weather do the rest.

If desperate, though, I guess I would consider a bug bomb. Most of these (especially the less nasty varieties) have a shelf life of maybe a year, so an old can won't help much.