We talked fly control - what about bees/wasps

In the last month or so, several wasp nests have been started in the barn. Each has 2-4 "guard" wasps that stick to the nest - but not a huge colony (yet). The ones that are low enough to reach are easily gotten with my bug zapper/swatter (like an electric tennis racket - VERY effective). Those that are beyond the reach of that, though, I am at a loss of what to do about them. I knocked a couple of them down this evening using a garden hoe to reach (there are a few that are beyond reach of even that, though). Some of them are in the feed area, over the hay, so I am hesitant to spray wasp killer because it will inevitably get on more than just the nest. Short of moving all the feed out and then blasting them with poison and the hose, what are the options?
I have an unreasonable fear of bees/wasps, so I'm not really keen on being up a ladder and unable to make a hasty get away if I tick them off.

I really don't know but I also have an irrational fear of bees. I've never been stung but they seriously cause me to run around screaming and I'm no screamer generally. You are not alone! I'd be terrified.

I hate wasps and bees too! I remember when I was little, I'd cry when I saw them. We generally just hose them down. I think that regular hosing like prevents the nest from getting too big and most of them drown in the water.

Can you lay a tarp over the feed and hay and then spray the nests? Typically once you spray they don't come back.

I would spray when the horses aren't in the barn. Make sure that you're well covered, or get a friend to do it for you since it sounds like you don't want any part of them!