Hot Shot 15 oz. Flying Insect Killer Aerosol kills flies, mosquitoes, and other flying insects fast. It kills mosquitoes and houseflies on non-porous surfaces for up to 4-weeks. The non-staining formula can be used indoors and outdoors to protect you from flying pests and the harmful diseases they may carry. For long-term protection, spray on window screens, doors, and window frames to kill insects that land on these surfaces.