Munchies are a species of intelligent, microscopic organisms that live in the shavings of the mineral marijuana. These organisms are the puppet masters who secretly control many aspects of human culture, including the internet. When Marijuana is converted into fuel, vibrators, or weapons in which to fight one's enemies, munchies are cast into the open air, where inhaled, they quickly enter the stomachs of bystanders, particularly bystanders in college or jam bands. Once injested, these organisms attach themselves to the host's brain, where breeding incessantly they create a compulsive need to consume, marry, and reproduce.
Only by wearing special sunglasses can you tell if someone has been infected with munchies, or if they are merely hungry.