So, the other day, I noticed this wasp building a nest on my balcony. I tried to hit it with a stick, but hit the roof, and scared the wasp off. He lingered around, so I threw water on it in order to knock it down and tried to stomp it, but it flew away. I then knocked down the bit of nest, kicked it off the balcony, and went back inside.
Later that evening, the wasp was back. In the same exact space, rebuilding it’s next. Unfortunately, I haven’t been able to kill it, but I do keep tossing water on it and it flies away. I then destroy the nest (well, what little of one there is, it’s never gotten more than the stem and a bit of the base).
The thing keeps coming back, and to the exact same spot. What’s the deal? Why, after being repeatedly chased off, does it keep returning to my porch? And more importantly, why does it keep going to the exact same spot?
It’s staked that piece of real estate as its home. As long as it continues to think of that spot as home, it will rebuild or repair the nest as often as necessary, and defend it, as well. A good dose of wasp killer spray should do the trick if you’re really against sharing your home with it.
Wasps aren’t that bright and your wasp is caught in a permanant loop: Get woodpulp, return to nest, add to nest, repeat until nest adequate size.
It has no memory of your actions or what size (if any) the nest was previously. So it’ll just keep building as long as you keep destroying.
The only way out of this is for one of you to die from exhaustion. 
If spraying the wasp with insecticide is not practical, it may be possible to use the extended tube of a vacuum cleaner and suck up the wasp when she returns to the proto-nest. As long as you keep destroying the nest, there will be no troublesome swarms of excited workers to deal with.
Thanks. I’m not too concerned about getting rid of the wasp, per se (one of these days my foot will be fast enough!), but I was more curious as to why the wasp keeps returning to the same spot? Do they put out some sort of “mark” in a location where they build a nest? Like I said, I’ve scared it off and removed what little of the nest it’s built a couple of times now, but it still returns to the same spot. Is there a biological reason for this, or is it like Futile Gesture says, and it just “Returns to work,” gets to the spot, thinks to itself “Self, I could have sworn I was building here. Oh well, may as well get started!” and that’s that. Or is there something more scientific to it?
I was googling for reasons why wasps choose certain locations and found this advice about handling wasps at picnics.
“Hang fish or liver on a string just over a bucket of water with detergent added to control yellowjackets at picnics. The yellowjackets will try to fly away with pieces of fish or liver that are too heavy for them, and will fall into the water. The detergent acts as a wetting agent, and trapped yellowjackets, unable to fly off, drown. This method is very effective.”
If my choice is between rotting fish or liver, and a few wasps, I’ll probably go with a few wasps.
Wasps sucked up in a vacuum cleaner does not always work. She crawls out in your house and sets up new territory.
It doesn’t work with flies either.
I use wasp and hornet spray and spray it a foot or so in each direction of the nest. I reaply after it rains until Miss Wasp gives up or is dead. Dead works better with spraying at night or spraying it right on her.