This summer provided the perfect conditions for the cicada killer wasp to set up shop in the courtyard between my house and garage, as well as all my neighbors yards. The sheer numbers made it impossible to combat this problem via home recipe. Griggs and brown agent showed up in timely manner and treated the area with a plant based deterrent. Wasps did vacate area after approximately six days. High marks for getting rid of the wasps. Also, I assume, the treatment is environmentally safe for both plant and animal life. The treatment does not appear to harm the wasps but makes the area intolerable for them. Still there are some female wasps returning and making new burrows. Would like more information about how to create conditions that would discourage their return in future.