I found a wasp nest in my chicken run and we want to spray it but are concerned then about the dead poisoned wasps that fall down in run and whether the spray will be toxic to the chickens???
I have been putting off spraying a huge nest of red wasps for about the same reasons. After a month of free ranging most all the girls were coming home to roost on their own but some went to playing hide and seek with their rent payments. They have only been in the pen a week for remedial training as to where they are supposed to lay, plus I've locked down a bunch of 5 month old pullets (that are due to lay) in the pen so the can be schooled by the Big Girls. Last thing I want to do is hurt any of them by spraying poison. Or have to re-catch those pullets.
I do know i had a friend who's son sprayed some wasps around the house and not thinking with chickens following closely behind half the flock die over the next 2 days.
If you decide you do have to spray... you need to clear the area of all chickens. And once completed clean up everything in the immediate area. Leave no bug dead or alive behind. And air the coop out throughly before letting the chickens in again.
So I posted the link previously as I thought it had some good replies, but wanted to add:
There are some sprays that will drop a wasp in mid flight, there contain strong nerve agents and are typically oily. Spray a mouse with this and it will convulse violently almost right away. Keep these away from your chickens.
There are other sprays that are intende to be sprayed on the nest after dark, they work differently, and if sprayed onto a wasp it will just fly away. Not sure if this typ is safe around chickens, but I would likobe safer than the other.
I would use one of the safer suggestions at the link I provided in the previous post if it were my chickens.