Itching is a protective body reflex, which warns the nervous system about potential threats or irritants, or dangers on the human skin. Itch on the skin is an irritating sensation and is caused by dry skin, which is commonly in elder people. We feel itch mainly by mosquitoes bites as mosquito injects saliva into the skin of human beings while drinking blood and this saliva in the blood and stops clotting in blood thus,mosquitoes can feed easily.

When mosquitoes injects saliva in the blood of human beings, our body recognizes proteins saliva of mosquitoes as a foreign invader, our immune system sends a chemical known as histamine to the bite area of the skin. This chemical histamine makes blood vessels expands and brings additional fluid to the bite area, which may cause swelling or a red bump. This chemical histamine irritates the nerves in our skin of human body, which sends itchy signal to our brain and may cause itch in our body.

There is only female mosquitoes bites human beings.