Why do mosquitoes itch after biting people?

When mosquitoes bite people, they inject several proteins into the human body, collectively known as mosquito saliva proteins. These proteins inhibit the body's blood clotting system, preventing blood clotting and preventing blood vessels from constricting so that mosquitoes can smoothly suck up the blood. After sucking the blood, the mosquito flew away, but the mosquito saliva protein remained in the human body.

The body's immune system is mobilized to try to remove these foreign substances, and an immune response occurs. In this process, a substance called histamine is released, which causes capillaries to dilate, increasing the permeability of the walls of blood vessels, filling cells with fluid, and inflammation occurs. At this time, the mosquito bite area is itchy, red and swollen.

If the mosquito does not carry the pathogen, the little blood sucked by the mosquito is negligible to the human. What is uncomfortable is the itching at the bite site, which is caused by the fact that the body's immune system does not need to make a big deal about the mosquito saliva protein, which is actually an allergic reaction. Some allergic reactions caused by mosquito bites are very fast, appearing within a few seconds of being bitten, but they also disappear quickly, and they are gone after a day; Some reactions appear a day later and last for days or even many days before disappearing.

Different species of mosquitoes cause different allergic reactions, some are heavy and some are light.

When summer comes, it is not only necessary to protect against the sun and heat, but the other is the annoying mosquito, and we must always beware of mosquito bites, so why do mosquito bites itch?

> almost everyone has the unpleasant experience of being "bitten" by mosquitoes, in fact, it should be said that they have been "stung" by mosquitoes. Mosquitoes can't open their mouths, so they won't bite on the **, it actually uses 6 needle-like structures to pierce people**, these short needles are the center of the mosquito's edible mouthparts.

These short needles suck human blood in the same way that they draw blood; The mosquito also releases saliva containing anticoagulants to prevent blood from clotting, so that it can feast peacefully. When the mosquitoes are full of food and drink and float away, all they leave behind is an itchy lump.

However, the itchy sensation is not caused by a short needle pricking or chemicals in the saliva. We feel itchy because the body's immune system releases a protein called histamine to fight foreign substances, and this immune response triggers an allergic reaction at the bite site. Histamine causes swelling of the tissues around the bite when blood flows to the bite site to speed up tissue recovery, and the intensity of this allergic reaction varies from person to person, with some people having a more severe allergic reaction to a mosquito bite.

Only female mosquitoes bite mammals because they have to suck blood every three or four days to get the protein they need to make eggs; Male mosquitoes mainly feed on nectar, while female mosquitoes use animal body heat and physiological changes to search for targets, which may be why human ankles and feet are more commonly bitten by mosquitoes, because the blood vessels in these parts are closer to the body surface, so more body heat is released.