Mosquitoes bite humans primarily because female mosquitoes need proteins from blood to develop their eggs. Male mosquitoes do not bite; they feed only on nectar. When a female mosquito bites, it pierces the skin to suck blood and injects saliva, which can cause itching and swelling as the body's immune system reacts to the saliva.
Why some people get bitten more than others depends on multiple factors:
- Blood type: People with Type O blood are generally more attractive to mosquitoes than those with Type A or B.
- Carbon dioxide: Mosquitoes sense exhaled carbon dioxide and are drawn to people who emit more, such as those who are larger or more active.
- Body odor and skin bacteria: Unique body odors, influenced by genetics and the types and amounts of bacteria living on the skin, can make some people more attractive to mosquitoes. Those with certain skin acids or specific bacterial profiles tend to get bitten more.
- Body temperature and sweat: Higher body heat and the presence of compounds like lactic acid and ammonia in sweat also attract mosquitoes.
In summary, mosquitoes bite to get the blood proteins needed for reproduction, and their preference for certain humans over others is based on factors such as blood type, carbon dioxide emission, skin odors, bacteria, and body heat.
