Most people experience some kind of skin reaction after being bitten by a mosquito. Only the female mosquito feeds on blood. When the female mosquito stabs her needle-like proboscis (a straw-like mouthpart) into our skin to suck out our blood, she injects us with her saliva. This is filled with digestive enzymes and anticoagulants, and it keeps blood flowing until she is finished with her meal. Our body reacts to the saliva by producing histamine. This makes the blood vessels near the bite enlarge, and so a pink, swollen, and itchy bump appears. When the blood vessels expand, nerves in the area become irritated by the swelling. We feel this irritation as an itchy sensation.