A simple mosquito repellant Get a large bottle of Listerine, pour into a 4-ounce spray bottle and use around areas outside. It works great and it's safe. It kills them instantly and will last a couple of days. Spray around food tables, play areas, standing water, anywhere you will be working or playing outside. Spray around door & window frames. Don't spray directly onto wood doors but do spray the frame around the door. This would also be a good thing to add to survival kits.