Most mosquitoes feed at dawn into the early evening, spring through late summer. There are species that feed both night and day. Adult male mosquitoes remain close to the breeding site and do not bite; females may fly long distances to find a blood meal. They seek wet or aquatic sites to lay eggs. Mosquitoes are attracted to the CO2 we exhale and can carry many diseases including Malaria, West Nile virus, Dengue fever and Yellow fever. Gnats and biting flies are found in regional sections of the US and are a nuisance during outdoor activities.