Female mosquitoes have piercing mouth parts through which they extract the blood of a host. The protein from gathered blood is used in egg production. Male mosquitoes do not have the ability to extract blood from a host.

While not particularly painful, the bite of a mosquito can prove dangerous to humans. When a mosquito inserts her proboscis through the skin, her saliva creates a small, red bump. These bumps produce mild to severe itching. Some people may become less sensitive to mosquito saliva through repeated exposure, while others may develop allergic reactions. Symptoms of an allergy include blistering and inflammation, as well as asthma-like reactions. Mosquitoes also carry diseases such as yellow and dengue fevers, malaria and encephalitis and are capable of passing them from host to host.