It sounds like you need to take action... If you don't want to pull the thatch apart and use a nest-killer spray or whatever, then-
I hate using poison, but when needs must...
You need to set up a container with poisoned bait so that the striped hooligans collect it and take it back to the nest to eventually destroy it. In the past I have had success by just sprinkling Rentokil PSW99 Wasp Killer Powder (Amazon about £5 if you can't find it a a garden center or whatever) onto crushed grapes in an ice cream tub with holes in it (wasps here are now in the 'sweet tooth' phase). Obviously, the bait needs to be something that does not appeal to bees, hoverflies etc.
Good luck.
I also found these more complicated instructions filed on my PC -I can't remember the source:
How to Make a Wasp poison trap.
This method will eradicate wasps or hornets and their nests within 1000 meters
without you going out to find each and every wasp nest to destroy them.
The principle is that foraging wasps take poisoned bait back to the nest to kill it.
HOW TO MAKE A SIMPLE WASP POISON TRAP
1. Container (can be a bucket, ice cream container, etc)
2. 4 skewers used for cooking meat long enough to go through one side of the container and out the other side.
3. Draw a line in center onside of container and a line directly opposite
this on the other side (180 degrees) drill 2 holes 6cm above bottom of
container 2cm apart 1 hole on the right side of the line 1 on the left side,
do this on the opposite side of container as well.
4. You will drill 4 more holes this time 2cm apart but 7cm from bottom on
the left and right of holes already drilled, then the 4 skewers go through
these holes the food will not roll off as you have created a cradle.
5. Wasp killer dust containing carbamate (Rentokil PSW99 Wasp Killer Powder) or permethrin will be needed as a poison in this trap.
6.Bait depends on the time of year. A can of dog or cat food, liver, etc early in the year or very ripe fruit later. These baits will not attract bees.
7. Under the cradle there is a gap.
On the bottom of the container you will sprinkle the dust (poison), do not
over do it as the Wasps need to make it back to the nest to spread the poison and kill the whole nest.
Do not get the poison on the cradle or you will put the Wasps off, put the
food onto cradle and put it out away from kids or animals but where
you have a Wasp Problem.
The system relies on greedy Wasps tearing off big pieces and dropping them into the bottom of the container before retrieving them before taking off to the nest with now poison coated food.
This System works so well it will destroy most Wasp Nests in under a week,
without you finding a single Nest, regardless of where the Wasps are coming
from as the wasps deliver the poison to the nest.
OK let me get on my soap box again!!
