Mosquito Bites
The red, itchy swellings associated with mosquito bites occur as a result of the body’s immune response to the bites. (Technically though, mosquitoes do not ‘bite’, they suck blood.) The mosquito will suck the blood into its abdomen where it will be used for the development of mosquito eggs.
How a Mosquito Bites
Female mosquitoes have specially adapted mouthparts to enable them to suck blood. (The act of an animal feeding on blood is known as haematophagy.) They use a long proboscis, which is a hollow, syringe-like part of their mouth for piercing human or animal skin. When they find a blood capillary, they suck the blood through the proboscis.
The proboscis is very thin with a serrated edge so it can pierce the skin, as easily and as discreetly as possible, making it unlikely you will notice a mosquito when it is actually feeding from you.
As well as sucking out blood, a mosquito injects saliva, which contains anti-coagulants to stop the blood from clotting. The saliva also contains an anti-inflammatory substance to numb the pain, so the act of sucking out the blood is not uncomfortable for the chosen host.
Why Mosquito Bites Itch
The itching red swelling, (mosquito bite) that appears when a mosquito has finished its meal is caused by an allergic reaction to the saliva that was injected, whereby the antibodies produced by the immune system of the host bind to antigens in the mosquito’s saliva. Within several hours of a mosquito bite the raised red swelling will appear, this is also known as a wheal or welt.
Reactions to Mosquito Bites
Some people are not sensitive to mosquito bites at all and will have little or no reaction, whereas others will have a very strong reaction and their mosquito bites will become very large, swollen and inflamed.
It is rare, but a few people have severe allergic reactions to mosquito bites that require medication.