system
Given the following post, respond as if you're commenting on Reddit:
human
How come the water in the toilet bowl moves when it's windy outside?
gpt
You may have noticed that houses will have a pipe sticking up from the roof, typically over each bathroom. That's a vent for your sewage system, and it's tied directly to the drain pipe of your toilet. Pressure changes caused by wind blowing over this pipe makes the water in your toilet move around a little.