Faucet Force GO!
Is there anything in your house you can't use to prank people? We don't think so, and it's because cool people like Collin keep showing us new ways to have fun with ordinary items! This one works by pranking the most automatic of everyday activities -- washing your hands after using the bathroom (and if that's not automatic for you IT REALLY SHOULD BE). People aren't really thinking when they do this, so they're not expecting anything exciting -- which makes this gag work so well!
People only expect water from this, not betrayal
Take some strong tape (duct tape works well) and carefully cover up the bottom of the faucet except for a small hole. This can be quite tricky -- you have to cut the tape so that it doesn't show from above, but it's worth it. By angling the hole you can make the water squirt in any direction you want, but if you choose any direction but "STRAIGHT AT THE PERSON" you're doing it wrong!