Causes

Mosquito bites are caused by female mosquitoes feeding on your blood. Female mosquitoes have a mouthpart made to pierce skin and siphon off blood. Males lack this blood-sucking ability because they don't produce eggs and so have no need for protein in blood.

As a biting mosquito fills itself with blood, it injects saliva into your skin. Proteins in the saliva trigger a mild immune system reaction that results in the characteristic itching and bump.

Mosquitoes select their victims by evaluating scent, exhaled carbon dioxide and the chemicals in a person's sweat.