Though we commonly call them mosquito bites, she's not really biting you at all. The mosquito pierces the upper layer of your skin with her proboscis, a straw-like mouthpart that allows her to drink fluids.

Once she breaks through your epidermis, the mosquito uses her proboscis to search for a pumping blood vessel in the dermal layer underneath.

When the mosquito locates a good vessel, she releases some of her saliva into the wound. Mosquito saliva contains anti-coagulants that keeps your blood flowing until she has finished her meal.

But what about the itching? When the blood vessels expand, the swelling irritates nerves in the area. You feel this nerve irritation as an itchy sensation.