Close all windows to homes and cars when you hear the truck coming or beforehand, they always do it after dark. So that there is no wind, but it still floats over everything. If you have a Moto of any kind, make sure you wipe off the handles and the seat in the morning. for years we have tried to find out what it is that they spray, but no one will commit to saying what it is. One of the officials in the water told me about closing all windows, etc. so I can imagine it is not an organic, safe substance.