World of Hippies.

This is a regular world, taxes, jobs, houses, everything, taking place in the 20th century, but there's a type of human that are treated like termites. They hide in walls and atics and basements, some are just in your back yard, and once there's one there's always more, and then more, until a whole house is filled with hippies. These "hippies" are basically just humans with low IQ, always getting high, but they're always calm, mostly, and they most giggle or laugh. There's different types of hippies, there'd the gigglers, there's the kazooers where it's they play kazoo's, the drummers which are often female and they like drumming, commonly in the backyard, and then there's the high'Es. The high'Es smoke 24/7 until they can barely think, unlike the rest, they're addicted, and slightly territorial. Hippies are capable of human language, but mostly use slang.

There's a few companies dedicated to getting rid of Hippies for people who don't want them, a humane way, or sometimes inhumane, and sometimes people keep them as roommates or other things.