Why does toilet water move when its windy outside?
barometric pressure differances between outside and inside, in a wind storm, lots of variences in pressure, there is a vent, that allows air in fromoutside to allow water to drain without any gulping of airfrom the drains, this vent allows outside pressure to be directly on the other side of the water plug the the s trap in the toilet forms(plug to keep sewer gases out of house) so when the pressure raises and falls just outside of the vent, the water moves up and down.
