Photo By João Trindade / CC BY 2.0

What's The Point in Making Us Itch!

Spring has been here for a while, but the actual spring weather is finally here, bringing with it all of the pesky bugs we all hate to deal with. No doubt, on the top of everyones list of bugs they hate are mosquitos and their itchy bites! So why do they bite, and why do those bites itch?

Well, to begin let's discuss why they bite in the first place. While it may seem like every mosquito you ever see is coming after you to bite, it is actually only the females that bite! The reason for this is because they need proteins and other special component of our blood in order to produce their eggs. One a female mosquito has landed on you and decided to take your blood, she uses her proboscis, which is like a tiny needle, to penetrate the skin, and move it around and search for a vein that she can take blood from. Once she has the blood she is able to fly off and the creation of her eggs for reproduction is able to commence.

So then why do they itch? Well, as the mosquito draws your blood from you, it also injects some of its own saliva into your blood. The reason it has to inject its own saliva is because it's worried it will get stuck inside your skin! The mosquitos saliva contains an anticoagulant, which means it keeps your blood from clotting. So, while the mosquito has its proboscis inside your skin, it releases its own anticoagulant saliva into your body so that your blood doesn't clot around it, and get the insect stuck. When your body recognizes that this mosquito saliva is a foreign body to you, and therefore should not be there it immediately starts attacking. Part of this attack involves releasing histamine. The histamine is what causes the itching, and also causes the area around the bite to swell up.



“Mosquito Facts: How and Why a Mosquito Bites You.”, 8 Aug. 2015,

Rabin, Roni Caryn. “Ask Well: Why Do Mosquito Bites Itch?” The New York Times, The New York Times, 3 June 2016,