I never accept to kill mosquitoes with chemical products. Why because these chemicals also effect to our body.especially childrens mostly effected to these products.i prefer natural method to kill mosquitoes. flash guard works very fast . Edpecially product spread smoke very soon it kill mosquitoes on that time if we r there smoke enters to our nose & start work to our body also. But it is small problem. But when we do like this we face many health problems so all my freinds chemical products use only emergency time