ome mosquitoes are harmful and can spread viruses like West Nile, dengue, Zika, and parasites like malaria. Other mosquitoes bother people and are considered “nuisance” mosquitoes. Nuisance mosquitoes bite people, but don’t spread germs. Of the over 200 types of mosquitoes in the United States and US territories, about 12 types spread germs.

Local government departments and mosquito control professionals track the numbers and types of mosquitoes in an area and the germs they may be spreading. When infected adult mosquitoes are spreading germs to people, acting quickly can stop further spread and prevent people from getting sick. Professionals share prevention information with the public and use multiple methods at the same time to kill mosquito larvae and adult mosquitoes.