Nothing ruins a night on the patio like being eaten alive by mosquitoes. They spread diseases such as malaria, encephalitis, West Nile, and the Zika virus. There are nearly 200 mosquito species in the United States. We typically think of mosquitoes being active in the evening. However, they are active both day and night and only female mosquitoes bite. The best way to keep safe is to eliminate mosquito breeding areas. The female lays her eggs in stagnant or slow-moving water, or on moist soil or leaf litter in wet areas.