Thats the thing I have been researching a little and I can put up a small bat house but there is no real answers on how many will show up. . I live next to a lot that is OVERGROWN with trees and a very small pond. When the skeeters start to attack is not fun to be outside. I spray off on my body and the go to my head. I spray on the head and they go to the face. I spray on my face and they go to my hands . I spray on my hands and they go in between my fingers . I spray all over my hands and they go up the bottom of my shorts . By the time I am done spraying off I am DIZZY from the chemicals.