The primary method of controlling A. aegypti is by eliminating its habitats. This is done by emptying containers of water or by addinginsecticides or biological control agents to these areas, although spraying with organophosphate or pyrethroid insecticides is not thought to be effective. Reducing open collections of water through environmental modification is the preferred method of control, given the concerns of negative health effect from insecticides and greater logistical difficulties with control agents People can prevent mosquito bites by wearing clothing that fully covers the skin, using mosquito netting while resting, and/or the application of insect repellent (DEET being the most effective).