It is not effective to spray during the day for several reasons. The primary reason is that the spray would be lifted away from the ground very quickly by the rising air currents that occur during hot days. At dusk and at night, the insecticide stays near the ground. The second reason is that most mosquitoes that bite during the day are breeding in containers or plants in the yard and are better controlled by eliminating the water in which they grow. Mosquito problems can be reduced by checking yards for containers, even very small ones that hold water. People should look for pet dishes, tin cans, flower pot holders, plugged gutters, tires, birdbaths, kiddy pools, toys, bromeliads, trash cans, etc. Water should be dumped every third day if the source is not eliminated. Containers that are too large to turn over should be covered. Daytime spraying is not practiced to avoid killing beneficial insects, particularly bees; to reduce people's and wildlife's exposure to the pesticide; and to eliminate the potential traffic hazard of a slow-moving vehicle during high traffic volume times. The mosquito control vehicle's slow-moving, flashing light and unique sound are easily seen and identified at night.