American Hydro Systems NS-1 NatureShield Insect and Pest Repellent, 1 Gallon All-Natural pest barrier for every landscape Repels unwanted pests for up to 5 days Control mosquitoes, ticks, fleas, ants, carpenter ants, centipedes, cockroaches, gnats, fire ants, silverfish and other crawling and flying insects Can be applied automatically through sprinklers with the ProFeeder or applied as needed with tank or boom sprayers or hose end sprayers For Outdoor Use! Potent Garlic Smell. If product is used in a system located indoors or in a garage, there will be a garlic smell in that area.