Was chatting to a council pest controller yesterday because i want to change jobs and have thought about pest control as a possible option, he showed me what he uses for wasp nests, a narcotic spray that fires about 10ft or so and drops em like fly's! the best invention ever according to him and he rekon's he's been in the business for 25yrs, god knows what was in it but i'm sure the resident pest controller will be able to tell you