I have been fighting this for serveral years. On warm windy days we get an strange smell that appears to come from under a window. The window is on the first floor and there is a basement below. Nowhere else does it smell. There does NOT appear to be a water leak and the smell has come even after a 5 week drought. The brick exterior has a layer of that fiber board material followed by plywood etc. At one point there were some ants in that area which I killed but it still smells! Without pulling down the wall is there anything I can do?