Boogers are comprised of various substances including mucus, dirt, air pollutants, bacteria, and more. Mucus (which is snot before it dries into a booger) serves to capture bacteria and other ...

Which get trapped by a layer of sticky snot that lines your nostrils. It's like fly paper for the flu. And as you continue to breathe, air hardens the mucus into a solid booger, a gooey prison ...