Indoor Residual Spraying or IRS is the process of spraying the inside of dwellings with an insecticide to kill mosquitoes that spread malaria. The insecticides used can be harmful to humans, animals and the environment, and last three to six months. The Butterfly Tree’s malaria prevention intervention, using a safe insecticidal coating, lasts up to two years and is harmless to humans and animals. As of 2015 we no longer provide funds for Indoor Residual Spraying.