The best time to kill adult mosquitoes by fogging is at dusk, when they are most active and looking for food. The aerosol fog primarily targets flying mosquitoes, which is why the timing of the spray is critical. A thermal fogger produces a thick pesticide fog or smoke by heating the fogging solution. It produces a nice insect fog that is directed to areas where it would like to kill mosquitoes, and other biting pests. During the fogging, flying mosquitoes within the treated area are killed. Although the local mosquito population is reduced for a few days,fogging does not prevent mosquitoes from re-entering the area.